5x 2x - Western Québec School Board 1 intro to... · Translating Words into an Algebra Expressions...
Transcript of 5x 2x - Western Québec School Board 1 intro to... · Translating Words into an Algebra Expressions...
Unit 1: Introduction to ALGEBRA
Give an algebraic expression for the perimeter
of each figure.
3x
3x 5x
2x
4x – 3 n
6n – 2
n + 3 n + 3
4x – 3
n
4x + 2 4x + 2
2x – 3
4n + 5 4n + 5
3x – 2 3x – 2
2n – 1
REMEMBER
You cannot ADD or SUBTRACT unlike terms
EXAMPLE: 6x – 4 + 8x
*Bring like terms together 6x + 8x – 4
14x – 4
14x – 4 is the simplified expression, we cannot
subtract 14x & 4 because they are unlike, 14x
is a variable term & 4 is a constant term
[number only]
n
4n + 7
SIMPLIFY each of the following algebraic expressions.
*Remember, you can ONLY + & — LIKE terms!
a + a + a
2b + 5b 4a + 2a + 5
x –x + x + 3
y + y + y + y + 2 + 5 3b + 2 – 2b – 3
–8a + 2a + 5
10b – 9b 3a + 2a + 3x
12a – 6a
15x – 10 2x + 8x
x + 2x + 5x
2a + 5 + 3a 20a + 18 + 2a + 5
–x + –7x
8t – 12t –8a – 12a
–18r – 12r
–7a – 9a –10c + 2c
Translating Words into an Algebra Expressions
Example: the sum of three times a number and eight means 3x + 8
Write an algebraic expression for each statement.
The sum of a number and six ______________
The quotient of fifteen and a number ______________
The difference between a number and twenty ______________
The product of seven and a number ______________
The difference between the square of a number and three _____________
The sum of triple z and double n ______________
One quarter of a number ______________
Three times a number decreased by nine ______________
Double a number less one hundred ______________
Ten less than half a number ____________
Translating Words into an Algebra Expressions
Example: twenty less than triple a number means 3x – 20
Write an algebraic expression for each statement.
The sum of double a number and two ______________
The quotient of twice a number and three ______________
The difference between fifty and a number ______________
The product of ten and a number ______________
The difference between five times a number and seven ___________
The difference of triple x and double z ______________
One third of a number ______________
Six times a number decreased by fifteen ______________
Triple a number less seventy ______________
Nineteen less than one quarter of a number ____________
Translating Words into an Algebra Expressions
Example: Fifteen less double a number means 15 – 2n
Write an algebraic expression for each statement.
The sum of five and seven times a number ______________
Ten more than two times a number ______________
Eight less than five times a number ______________
The product of three times a number and four ______________
Eleven less than four times a number ______________
The square of the sum of six times and two ______________
One fifth of a number ______________
The sum of a number and twice the same number ______________
The sum of an even number & the next even number ______________
The sum of a number & the next two consecutive numbers __________
SIMPLIFY each of the following; SIMPLIFY means to combine LIKE TERMS.
6x + 3x
–6n + –5n 15s + –4s
–7b – –4b 9x – –2x –5n – 8n
1 + 3x – 5x + 7
x – 1+ 4x – 6 7x + 8 + 3x – 3
8 + 2x + x – 3
7x – 10 – 3x + 5 –4x – 6 – 4x + 1
6x + 4 – 3x – 9
–6n + 3 + 9 – 2n
–10 – 4x + 5x +6
3s + 6s – 13 + 5
2t – 10 – 6t 8 – 3x – 7x
Algebraic Expressions in Word Problems The rate for a taxi is $5.00 plus $1.35 for each kilometer traveled. Write a simplified algebraic
expression to represent the cost of a taxi ride for x kilometers.
Jason sold x yearbooks the first week, he sold double that in the second week and during the
third week he sold 5 less than during the second week. Write an algebraic expression for each
week and then write a simplified expression to represent the total number of yearbooks that
Jason sole.
Week #1: ____________ Simplified expression:
Week #2: ____________
Week #3: ____________ Pencils cost p¢ each [taxes included]. How many pencils can be purchased for $d?
If a represents a person’s age in years, give an expression to represent the person’s age:
a) in months? b) in days?
If a student has x classes in n days, how many classes does the student have per day?
Todd weighed x kg and lost n kg in each of four consecutive weeks. Give an algebraic
expression to represent Todd’s weight after four weeks.
If there are x boys and n dogs in the park, write an algebraic expression to represent the total
number of feet in the park.
Write an algebraic expression to represent your average on math tests where you scored, x %,
n % and y %.
SIMPLIFY each of the following:
(2x + 4) + 6 (3x + 1) + 3x
(4x – 2) + 4
x + 3 – 2x 8x + 5x + 5 – 2
(x + 3) + (4x + 2)
(5x + 4) – (2x + 2) (6x – 5) + (x – 2)
11x – (9x – 4)
(8x + 7) – (9x + 3) (8x – 10) – (7x – 12)
STEPS to REMEMBER
EXAMPLE: (6x – 4) – (8x + 3)
*Notice minus sign between brackets
Step 6x – 4 – 8x – 3 Remove brackets & make necessary changes
Step 6x – 8x – 4 – 3
*Bring LIKE TERMS together Step -2x – 7
*Simplified, cannot subtract unlike terms!
(2x – 5) – (9 – 7x) 14x – (20x + 3)
(3x – 1) + (5x – 4) (x + 3) – (3x + 1)
(x + 1) + (2x + 4) (x – 2) – (2x – 3)
2x 4 + 3x + 8 5x (4x – 7) – (8x – 9)
12x 9 + 7x + 15 15x (6x – 3) – (11x – 10)
Simplifying Algebraic Expressions
MULTIPLICATION & DIVISION Remember: You can MULTIPLY or DIVIDE unlike terms!
7 • –6s
–5x • –9
4 • –3x
15n ÷ –5
16
64
m
–84x ÷ 12
6 • 2x
–3x • 5 –8 • –9x
–2(4x + 3)
–1(5x – 9)
4(4x – 2)
(15x + 9) 3
5
)1025( x
(–21 – 14x) 7
REMEMBER: You CAN multiply &
divide unlike terms
EXAMPLE : 9 15x
135x
*Multiply the integers, then include
variable & you have the expression
EXAMPLE : -56x 8
-7x
*Divide the integers, then include variable
& you have the expression
9 • –15s
–3n • –12 –8 • 7x
24n ÷ –8
10
60
m
–81x ÷ 9
9 • 6x
–3x • 14 –12 • –9x
–4(5x + 6)
–7(2x – 9) 8(3x – 2)
–3(7x + 4)
–1(8x – 7) –5(9x – 12)
3
)3312( x
(20x – 35) 5
9
)1854( x
2(x – 8) – 3(4x – 2)
2(4x + 5) – 3(x + 2)
3(2x – 5) + 4(x + 1)
7(3x + 2) + 4(5x – 5)
9(2x – 3) – 8(4 – 5x)
4(6 + 8x) – 3(5 – 7x)
5(2x + 1) – 4(x – 3) + 8(2 – 3x) – 4(3 – 5x)
Algebraic Expressions in Word Problems A repairman earns $x per hour plus $30 for traveling expenses. Write an algebraic expression
to represent a bill for 7 hours of work (excluding taxes).
Sophie buys x packages of graph paper for $2.55 each (tax included). She pays with a $20
bill. Write an algebraic expression to represent the amount of change the cashier should give
back to Sophie.
Jasmine pays $x for one dozen multigrain bagels. Write an algebraic expression to represent
the cost of 5 bagels.
Sam sells tickets for the Hadley Junior High School Fall Talent Show, he sells (3x – 4) $3
tickets and (2x + 5) $4 tickets. Write a simplified algebraic expression to represent the
money Sam made.
Simplify each of the following expressions. *Remember: The minus sign between the brackets means the sign inside the brackets changes to the opposite of
what is was, + to — or — to +
(5x + 4) – (x – 2) (6 – 3x) + (x – 5x)
(4x + 5) – (3x – 2) – 6 9x + 5 – 7x
2 • –7x 3(2x – 6)
7x – 4(x + 2) (12x – 6) 3
2
)8610( x
2(3x – 2) + 3(x + 5)
Find the simplified algebraic expression for the perimeter of this polygon.
3x + 4
2x – 5
6 – x
4x + 1
8 – 6x
B I N G O
ALGEBRA
BINGO
On the next page are a series of Algebraic Expressions and Phrases.
1. Cut out each of the expressions and phrases;
2. Match each phrase to an expression;
3. Glue 24 of the algebraic expressions to the above BINGO card;
4. Get some bingo chips & you are ready to play ALGEBRA BINGO!
Cut out each of these rectangles, there are 52 expressions and phrases in total.
After you cut them out, match the expression with the phrase. Once your teacher
has checked your matches you will glue JUST the expressions onto your BINGO card!
5 + x Double a number
decreased by 5 6 – x Six times a number less
one
6(x + 1) The quotient of
three and a
number less two
4x – 2 Product of six and a
number decreased by
1
2x – 5 Six less a number 9 + x Five times a number
plus 1
4x + 3 Nine minus five
times a number (x – 2)2 The square of a
number minus three
6x – 1 Five more than a
number 8 – x Four times a number
decreased by 2
x + 6 Nine increased by
a number 2 – 3x A number divided by
six
5 – 2x Eight decreased by
a number 2(x + 5) Seven decreased by
two times a number
)2(
3
x
Two less than
three times
number 6
x
Three times a number
plus two
2x - 6 The difference
between triple x
and double n
9 – 5x Three more than
quadruple a number
x – 5 Two times five
more than a
number
7 – 2x Eight less than the
cube of a number
3x – 2 Five minus double
a number 3(x + 2) Five less than a
number
3x – 2n Six less than
double a number x2 – 3 The square of a
number decreased by
two
Unit 1 Extra Practice
10x – 8x + 7x + 2 (3y + 5) + (7y – 8)
(12a + 6) – (8a – 4) 11n + 5 – 9n + – (7n + 4)
7u – 2(u + 5) 3(y – 2) + 5(6 + y)
(4x + 10) – 2(3x – 5) (24n – 16) ÷ 4
y + (y + 4) + (y – 4) 5(2x) + 3(3x – 4) – 6(7x)
(8x – 6) – (3x – 6) (4s – 5) – (4s – 5)
(8 – n) + (n – 8) + 4n 3(5 – 2x) – 6(x + 8)