Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of...

39
Tony Hren Algebra 1 Review May 14, 2010

Transcript of Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of...

Page 1: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Tony HrenAlgebra 1 ReviewMay 14, 2010

Page 2: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Addition Property (of Equality)

Multiplication Property (of Equality)

If the same number is added to both sides of an equation, the two sides remain equal.

Example: If a=b, then a+c = b+c

You can multiply both sides of an equation by the same nonzero number,

and this won't change the truth of the equation.

Example: If a=b, then ac=bc

http://www.icoachmath.com/sitemap/Addition_Property_of_Equality_and_Inequality.html

http://www.onemathematicalcat.org/algebra_book/online_problems/mult_prop_eq.htm

Page 3: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Reflexive Property (of Equality)

Symmetric Property (of Equality)

Transitive Property (of Equality)

Example: a=a

Example: If a=b, then b=a

Example: If a=b, and b=c, then a=c

Page 4: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Associative Property of Addition

Associative Property of Multiplication

The property which states that for all real numbers a, b, and c, their sum is always the same, regardless of their grouping.

Example: (a + b) + c = a + (b + c)

The property which states that for all real numbers a, b, and c, their product is always the same, regardless of their grouping.

Example: (a x b) x c = a x (b x c)

http://www.harcourtschool.com/glossary/math_advantage/definitions/associative_add7.html

http://www.harcourtschool.com/glossary/math_advantage/definitions/associative_mul7.html

Page 5: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Commutative Property of Addition

Commutative Property of Multiplication

The Commutative Property of Addition states that changing the order of addends does not change the sum

Example: if a and b are two real numbers, then a + b = b + a.

The Commutative Property of Multiplication states that changing the order of the factors does not change the

product.

Example: if a and b are two real numbers, then a × b = b × a.

http://www.icoachmath.com/SiteMap/CommutativePropertyofAddition.html

Page 6: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Distributive Property (of Multiplication over Addition)

The property which states that multiplying a sum by a number gives the same result as multiplying each

addend by the number and then adding the products.

Example:

a(b + c) = a X b + a X c http://www.harcourtschool.com/glossary/math_advantage/definitions/distributive_p7.html

Page 7: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Property of Opposites or Inverse Property of Addition

Prop of Reciprocals or Inverse Prop. of Multiplication

The property that states the sum of a number and its opposite is always zero.

Example: a+(-a)=0

For every non-zero real number a there is a unique real number 1/a such that:

Example: a( )=1

http://www.washoe.k12.nv.us/ecollab/washoemath/dictionary/vmd/full/a/dditionpropertyofopposites.htm

1

ahttp://everyonehatesmath.com/property-of-reciprocals/

Page 8: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Identity Property of Addition

Identity Property of Multiplication

Identity property of addition states that the sum of zero and any number or variable is the number or variable itself.

Example: a+0=a

Identity property of multiplication states that the product of 1 and any number or variable is the number or variable itself.

Example: 4 x 1=4

http://www.northstarmath.com/Sitemap/IdentityPropertiesofAdditionandMultiplication.html

Page 9: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Multiplicative Property of Zero

Closure Property of Addition

Closure Property of Multiplication

Any number multiplied by zero equals zero.

Example: a(0)=0

Closure property of addition states that the sum of any two real numbers equals another real number.

Example: If a and b are real numbers, then a + b equals a real number.

Closure property of multiplication states that the product of any two real numbers equals another real number.

Example: If a and b are real numbers, then a x b is equal to a real number.

Page 10: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Product of Powers Property

Power of a Product Property

Power of a Power Property

This property states that to multiply powers having the same base, add the exponents.

Example: for a real number non-zero a and two integers m and n, am × an = am+n.

This property states that a product of a power can be obtained by finding the powers of each property and multiplying them.

Example: (ab)m = am × bm

This property states that the power of a power can be found by multiplying the exponents.

Example: (am)n = amn

http://www.icoachmath.com/sitemap/Power_Properties.html

Page 11: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Quotient of Powers Property

Power of a Quotient Property

This property states that to divide powers having the same base, subtract the exponents.

Example:

This property states that the power of a quotient can be obtained by finding the powers of numerator and denominator

and dividing them.

Example:

          . http://www.icoachmath.com/sitemap/Power_Properties.html

Page 12: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Zero Power Property

Negative Power Property

When a number is raised to the zero power, it is always equal to 1.

Example: a0=1

To solve for negative exponents, write the reciprocal of the expression, and change

the negative to the positive power.

Example:

                                 

http://www.mathsisfun.com/algebra/negative-exponents.html

Page 13: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Zero Product Property The Zero Product Property simply states that if ab = 0, then either a = 0 or b = 0 (or both). A product of

factors is zero if and only if one or more of the factors is zero.

Example: ab=0. If this is true, a, b, or a and be must be equal to zero.

Page 14: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Product of Roots Property

Quotient of Roots Property

The factors of the square root of a number are equal to the square root of one factor of the original number multiplied by the square root of another.

= XExample:

The roots of a square root of a quotient are equal to the square root of the numerator written over/divided by the square root of the denominator.

=Example:

http://www.tutorvista.com/math/square-root-property-calculator

Page 15: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Root of a Power Property

Power of a Root Property

Example:

http://hotmath.com/hotmath_help/topics/properties-of-exponents.html

a4 = a2 x a2 = (a)(a)(a)(a)

Example:

Page 16: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

PROPERTY QUIZ!

Page 17: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

1.) (am)n = amn

Power of a Power Property

Click when you’re ready for the answers.

2.) If a=b, then b=a Symmetric Property (of Equality)

3.) If a=b, then a+c = b+c

Addition Property (of Equality)

4.) a+(-a)=0Property of Opposites/Inverse Operation of Addition

5.) If a=b, then ac=bc

Multiplication Property of Equality

6.) If a=b, then ac=bcMultiplicative Property of Zero

7.) If a=b, and b=c, then a=c

Transitive Property of Equality

8.) (a x b) x c = a x (b x c)

Associative Poperty of Multiplication

9.) If a and b are two real numbers, then a × b = b × a.

Commutative Property of Multiplication

10.) If a and b are two real numbers, then a + b = b + a.

Commutative Property of Addition

11.) a(b + c) = a X b + a X cDist. Prop. (of Multiplication over Division)

12.) a0=1

Zero Power Property

Page 18: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Solving 1st Power Inequalities in One Variable

-With only one inequality sign

http://www.mathsteacher.com.au/year10/ch02_linear_equations/07_subtract/solve.htm

As shown below, x > 4. This is the answer because after dividing each side by 6, we are left with x > 4.

Example: 6x > 24A linear equation has only one value for the solution that holds true. For example, the linear equation 6x = 24 is a true statement only when x = 4. However, the linear inequality 6x > 24 is satisfied when x > 4. So, there are many values of x which will satisfy the inequality 6x > 24, which is the same thing as x > 4, which is the answer.

Page 19: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Another Example

The solution set consists of all numbers less than or equal to –2, as shown on the following number line.

http://www.mathsteacher.com.au/year10/ch02_linear_equations/07_subtract/solve.htm

Page 20: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Special Case: Division and Multiplication of Negative Numbers• With only one inequality sign

• if an inequality is multiplied (or divided) by the same negative number, then:

http://www.mathsteacher.com.au/year10/ch02_linear_equations/07_subtract/solve.htm

Example: -3x > 27[Divide each side by (-3)]

Answer: x < -9

Page 21: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Conjunctions

• Must satisfy both conditions of the inequality

http://image.tutorvista.com/Qimages/QD/28881.gif

Graph A: 4 ≤ x < 9

Graph B: 4 < x ≤ 9

Graph C: 4 < x < 9

Graph D: 4 ≤ x ≤ 9

RESULT:

Examples:

Page 22: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Disjunctions

• Must satisfy either one or both of the conditions

http://hotmath.com/images/gt/lessons/genericalg1/f-352-21-ex-1.gif

Example: x ≤ -3OR x > 2

< AND > have open endpoints, while ≥ and ≤ have closed endpoints

Page 23: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Special Cases

• If there are no solutions that work, the answer is Ø

• If every number works, the answer is {reals}

• If there is a disjunction in the same direction, only one arrow is needed

Page 24: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Linear Equations with Two VariablesSlopes and Equations of Lines

Positive: Lines that rise as you move from left to right.

Negative: Lines that fall as you move from left to right.

Rising and Falling lines are associated with rise/run (rise over run) which is the same as the difference between y-coordinates/difference between x-coordinates.

Horizontal Lines: Each of these has a slope of 0, and refers to a straight line from left to right.

Vertical Lines: Each of these has no slope, and refers to a straight line running up and down.

Positive Negative Vertical Horizontal

http://www.google.com/imgres?imgurl=http://www.learningwave.com/lwonline/algebra_section2/graphics/typesslope2.gif&imgrefurl=http://www.learningwave.com/lwonline/algebra_section2/slope2.html&usg=__fF7XXBj0ZQWoDV0dCqXQObS45x8=&h=192&w=203&sz=6&hl=en&start=5&um=1&itbs=1&tbnid=NLy_ChIj2-lDfM:&tbnh=99&tbnw=105&prev=/images%3Fq%3Dthe%2B4%2Btypes%2Bof%2Bslopes%26um%3D1%26hl%3Den%26sa%3DN%26ndsp%3D20%26tbs%3Disch:1

Page 25: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Point-Slope formula:

http://www.saskschools.ca/curr_content/matha30rev1/lesson3-4/ponitslopeformula.jpg

Standard Form Ax + By = C

A, B, C are integers (positive or negative whole numbers) No fractions nor decimals in standard form.

Traditionally the "Ax" term is positive.

http://www.algebralab.org/studyaids/studyaid.aspx?file=algebra1_5-5.xml

In the slope-intercept formula, the equation is y=mx+b., whereas ‘m’ is equal to the slope, ‘b’ is the y-intercept and the ‘y’ and ‘x’ are the coordinates. Start graphing by placing a point on the y-intercept. Then follow the slope to make your line. The x-intercept is where on the x-axis the line passes through.

How to Graph and find Intercepts?

Page 26: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Linear SystemsSubstitution Method: First solve one equation for one of the variables. Substitute this expression in the other equation and solve for the other variable next. Then, substitute this value in the equation of the first step and solve. Example: z=4y-4

Page 27: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Addition/Subtraction Method (Elimination Method): First add the similar terms of the two equations to find the x. Then solve the resulting equation. Substitute that answer for the other variable to find y. Then check your final answers in both equations.

Terms QuizChoices: dependent, inconsistent, consistent1.) A system in whichthe solution id all points on the line

dependent

2.) A system in which the lines cross on one point.

consistent

3.) A system which is false or null set because it is parallel

inconsistent

Page 28: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

FactoringGCF: For any number of terms, factor first the common factors of

the expressions, and then fill in what is left over.

Difference of Squares: For binomials, first find the GCF, then find the squares and simplify what is left over, hopefully finding conjugates.

Sum or Difference of Cubes: For binomials, simply find the square or cube root from each side.

PST: For trinomials, If 1st & 3rd terms are squares and the middle term is twice the product of their square roots, use this method by reverse foil.

Reverse Foil: for trinomials, do the opposite of F O+I L.

Factor By Grouping: Usually do this with 4 or more terms, and take the roots of the algebraic expressions.

Page 29: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Rational Expressions

• To simplify a rational expression:

• Completely factor numerators and denominators.

• Reduce common factors.

• Example : Simplify

http://www.cliffsnotes.com/study_guide/Simplifying-Rational-Expressions.topicArticleId-38949,articleId-38901.html

Examples:Addition: 3/5 + 1/5 = 4/5.Subtraction: 11/12 – 4/12 = 7/12.Division: ¾ / 2 = ¾ x ½ =3/8.Multiplication: ¾ x ¾ =9/4 = 2 and ¼.

Page 30: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Quadratic Equations in one Variable

Factoring: x2+5x+6=0 = (x+2)(x+3)=0

(-2, -3)

Taking Square Root of each side:x2= 4x=2.Completing the Square:(x – 4)2 = 5 x – 4 = ± sqrt(5) x = 4 ± sqrt(5) x = 4 – sqrt(5)  and  x = 4 + sqrt(5) http://www.purplemath.com/modules/sqrquad.htm

Quadratic Formula

http://www.sosmath.com/algebra/quadraticeq/quadraformula/quadraformula.html

The discriminant tells you how many X-axis intercepts a polynomial function has.

Page 31: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

FunctionsF(x) means the same thing as “y” but gives more information. The expression

"f(x)" means "plug a value for x into a formula f "; You solve it the same way you would for a “y”. Not all relations are function.

y = √(x + 4) The domain of the function is x ≥ −4, because x cannot take values less than -4. the range for this function is y ≥ 0, because There is no value of x that we can find such that we will get a negative value of y. In order to find a linear equation when given two pairs of data, follow the rule:y2-y1/x2-x1. For example if you had the ordered pairs (2,3) and (1,5), you would first do 5-3, which is equal to 2, over 1-2, which is equal to -1, which is the slope.  Then substitute zero for one of the values and solve for x and y.

http://www.intmath.com/Functions-and-graphs/2a_Domain-and-range.php

Page 32: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Parabolas• WRITE YOUR EQUATION ON PAPER. IF NECESSARY, TRY TO REARRANGE THE EQUATION INTO

THE FORM OF A PARABOLA, Y - K = A (X - H)^2. (OUR EXAMPLE IS Y - 3 = - 1/6 (X + 6)^2, WHERE ^ DENOTES AN EXPONENT.)

• FIND THE VERTEX OF THE PARABOLA. THE VERTEX IS THE EXACT CENTER OF THE PARABOLA, THE KEY COMPONENT. USING THE FORMULA FOR A PARABOLA, Y - K = A (X - H)^2, THE VERTEX X-COORDINATE (HORIZONTAL) IS "H" AND THE Y-COORDINATE (VERTICAL) IS "K." FIND THESE TWO VALUES IN YOUR ACTUAL EQUATION. (OUR EXAMPLE IS H = -6 AND K = 3.)

• FIND THE Y-INTERCEPT BY SOLVING THE EQUATION FOR "Y." SET "X" TO "0" AND SOLVE FOR "Y." (OUR EXAMPLE IS Y = -3.)

• FIND THE X-INTERCEPT BY SOLVING THE EQUATION FOR "X." SET "Y" TO "0" AND SOLVE FOR "X." WHEN TAKING THE SQUARE ROOT OF BOTH SIDES, THE SINGLE NUMBER SIDE OF THE EQUATION BECOMES BOTH POSITIVE AND NEGATIVE (+/-), RESULTING IN TWO SEPARATE SOLUTIONS, ONE USING THE POSITIVE AND ONE USING THE NEGATIVE.

• DRAW A BLANK LINE GRAPH ON GRAPH PAPER. DETERMINE THE SIZE ANDAREA OF THE GRAPH. A PARABOLA GOES TO INFINITY, SO THE GRAPH IS ONLY A SMALL PORTION NEAR THE VERTEX, WHICH IS THE TOP OR BOTTOM OF THE PARABOLA. THE GRAPH NEEDS TO BE DRAWN IN PROXIMITY TO THE VERTEX. THE X AND Y-INTERCEPTS TELL THE ACTUAL POINTS THAT APPEAR ON THE GRAPH. DRAW A STRAIGHT HORIZONTAL LINE AND A STRAIGHT VERTICAL LINE INTERCEPTING AND PASSING THROUGH THE HORIZONTAL LINE. DRAW AN ARROW AT BOTH ENDS OF BOTH LINES TO REPRESENT INFINITY. MARK SMALL TICK LINES ON EACH LINE AT EQUAL INTERVALS REPRESENTING NUMERAL INCREMENTS IN THE VICINITY OF THE SIZE OF THE COORDINATES. MAKE THE GRAPH A FEW TICKS LARGER THAN THESE COORDINATES.

• PLOT THE PARABOLA ON THE LINE GRAPH. PLOT THE VERTEX, X-INTERCEPT, AND Y-INTERCEPTS POINTS ON THE GRAPH WITH LARGE DOTS. CONNECT THE DOTS WITH ONE CONTINUOUS U-SHAPED LINE AND CONTINUE THE LINES TO NEAR THE END OF THE GRAPH. DRAW AN ARROW AT BOTH ENDS OF THE PARABOLA LINE TO REPRESENT INFINITY.

http://www.ehow.com/how_4546044_graph-parabola.html

Page 33: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

http://www.algebralab.org/lessons/lesson.aspx?file=algebra_radical_simplify.xml

Simplify (–46x2y3z)0 This is simple enough: anything to the zero power is just 1.(-46x2y3z)0 =1

Simplifying Expressions with Exponents and Radicals

=

x6 × x5 = (x6)(x5)              = (xxxxxx)(xxxxx)    (6 times, and then 5 times)             = xxxxxxxxxxx         (11 times)              = x11  

Radical Expressions Examples

Page 34: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Many single-variable algebra word problems have to do with the relations between different people's ages. For example: Al's father is 45. He is 15 years older than twice Al's age. How old is Al?We can begin by assigning a variable to what we're asked to find. Here this is Al's age, so let Al's age = x. We also know from the information given in the problem that 45 is 15 more than twice Al's age. How can we translate this from words into mathematical symbols? What is twice Al's age? Al's age is x, so twice Al's age is 2x, and 15 more than twice Al's age is 15 + 2x. That equals 45. Now we have an equation in terms of one variable that we can solve for x: 45 = 15 + 2x.

original statement of the problem:  45 = 15 + 2x

subtract 15 from each side: 30 = 2x

divide both sides by 2: 15 = x

Since x is Al's age and x = 15, this means that Al is 15 years old

Word Problems

Page 35: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Ned got a 12% discount when he bought his new jacket. If the original price, before the discount, was $50, how much was the discount? Word problems tend to be even wordier than this one. The solution process involves making the problem simpler and simpler, until it's a math problem with no words. Step 1. Identify what they're asking for, and call it x. x = amount of the discount. Step 2. Use the information given to write an equation that relates the quantities involved. 12% of 50 dollars = the amount of the discount (x). Step 3. Translate into Math:(12/100) * 50 = x. Step 4. Solve for x:6 = x. This means that Ned's 12% off amounted to a $6 discount.

Word Problems (cont.)

http://www.algebra.com/algebra/homework/Percentage-and-ratio-word-problems/Percentage-Word-Problems-(discount).lesson

Page 36: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Adding To The Solution Mixture Problems: Example 1: John has 20 ounces of a 20% of salt solution, How much salt should he add to make it a 25% solution?Solution: Step 1: Set up a table for salt.

 

original

added result

concentration

     

amount      

Step 2: Fill in the table with information given in the question.John has 20 ounces of a 20% of salt solution. How much salt should he add to make it a 25% solution?The salt added is 100% salt, which is 1 in decimal.Change all the percent to decimalsLet x = amount of salt added. The result would be 20 + x.

 

original

added result

concentration

0.2 1 0.25

amount 20 x 20 + x

Step 3: Multiply down each column.

 

original

added result

concentration

0.2 1 0.25

amount 20 x 20 + x

multiply 0.2 × 20

1 × x 0.25(20 + x)

Step 4:original + added = result0.2 × 20 + 1 × x = 0.25(20 + x)4 + x = 5 + 0.25xIsolate variable xx – 0.25x = 5 – 40.75x = 1

Answer: He should add      ounces of salt.

Word Problems (cont.)

http://www.onlinemathlearning.com/mixture-problems.html#add

Page 37: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

You put $1000 into an investment yielding 6% annual interest; you left the money in for two years. How much interest do you get

at the end of those two years? In this case, P = $1000, r = 0.06 (because I have to convert the

percent to decimal form), and the time is t = 2. Substituting, I get:I = (1000)(0.06)(2) = 120

I will get $120 in interest.You invested $500 and received $650 after three years. What had

been the interest rate? For this exercise, I first need to find the amount of the interest. Since interest is added to the principal, and since P = $500, then I = $650 – 500 = $150. The time is t = 3. Substituting all of these values into the

simple-interest formula, I get:150 = (500)(r)(3)

150 = 1500r 150/1500 = r = 0.10

Of course, I need to remember to convert this decimal to a percentage.I was getting 10% interest

Word Problems (Cont.)

http://www.purplemath.com/modules/percntof.htm

Page 38: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

Line of Best Fit

A line of best fit  is a straight line that best represents the data on a scatter plot. 

This line may pass through some of the points, none of the points, or all of the points.

A graphing calculator helps because if you enter information correctly, it will draw one for you.

 Here's an example.Suppose you want to find out whether more hours spent studying will have an affect on a person's mark.You set up an experiment with some people, recording how many hours they spent studying and then recording what happened to their mark.You can see the data in the table at the right.It's difficult to see any pattern in the table, although it's clear that different things happened to different people. One person studied for 1 hour and had their mark go up 2%, while another person who also studied for 1 hour saw a drop of 1%!

Page 39: Tony Hren Algebra 1 Review May 14, 2010. Addition Property (of Equality) Multiplication Property (of Equality) If the same number is added to both sides.

I HOPE YOU ENJOYED THIS

BEAUTIFUL ALGEBRA 1 PRESENTATION!

The end.