8th Grade Algebra: Linear Expressions Juan Carlos LozanoEDU 346Powerpoint (Alg_8.1)

Lesson Plan Overview• 8th grade Algebra Class• Linear equations with one, or more variables• Demonstrate in class, non-linear powerpoint will

be used as a resource to assist learners outside of class

• Absent students benefit• Reflection from students the next day

Lesson Plan Overview• Common Core Math Standards• CCSS.Math.Content.8.EE.C.7 Solve linear equations in one

variable.• CCSS.Math.Content.8.EE.C.8 Analyze and solve pairs of

simultaneous linear equations.• (Intro to) CCSS.Math.Content.8.EE.C.8b Solve systems of

two linear equations in two variables algebraically, and estimate solutions by graphing the equations. Solve simple cases by inspection. For example, 3x + 2y = 5 and 3x + 2y = 6 have no solution because 3x + 2y cannot simultaneously be 5 and 6.

8th Grade Algebra: Linear Expressions

Table of Content

• Home• Variable introductio

n• Linear equations wi

th one variable• Linear equations re

al life examples• How to solve linear

equations with one variable

• Practice with one variable linear equations

• Linear equations with two variables

• How to solve linear equations with two variables

• Practice with two variable linear equations

Variables! What is it good for!?• Variables is a lot like a box, and it exists to contain a

value. Sometimes the value is already inside the box, and you have to figure out what that value is. Other times, the box is empty, and you get to pick the value to put inside.

• Remember when you were in elementary school, and you were learning your addition? The teacher would hand you worksheets that said things like:

(?) + 2 = 5 ; fill in the ?. The ? Plays as a variable, and can be expressed in almost any form, usually letters, especially x, y, and z.

HomeTOC Linear equations with one variableHow to solve linear equations with one variable

Linear Equations With One Variable

• X+4=5

• Y-2=3

• 9-z=6

• 7+p=10

• 8=m+4

• 10=15-b• Home• TOC• Linear Equations Re

al Life Examples• How to solve linear

equations with one variable

Real World Uses Linear Equations!

• You are in busy New York City, and looking for a cab to take you home. The cab driver charges $10 and $2 for each mile driven. You live five miles away. How much will it cost you to get home?

• Banks• Interest rates and investments

• Currency exchange rates

• Price changes (grocery stores)

Home TOC How to solve one variable linear equations

Click me for a better explanation

How To Solve Linear Equations With One Variable• Step 1: Locate the variable• Step 2: Determine what needs to be done to isolate the

variable from the number on the other side of the “=“• Step 3: Compute the arithmetic needed to isolate variable• Step 4: Make sure variable stands alone, and equals

something

I’m getting closer, show me!Whoa! What’s a variable?Got it! Let’s move on to two variable linear equations!

HomeTOC Linear equations with two variables

One Variable Linear Equations• Using the example, x+2=7• Step 1: locate the variable

• X is the variable, we will be solving for x

• Step 2: determine what needs to be done in order to isolate the variable• We need to get rid of the (+2)

• Step 3: Do the arithmetic needed to isolate variable, remember, what you do to one side of the equation, you MUST do to the other!• X+2=7• -2=-2• X=5

Step 4: Make sure variable stands alone and equals somethingCheck!

Practice solving for linear equations with one variable

Home TOC Linear equations with two variables

Linear Equations with Two Variables• Now that you are comfortable with one variable

linear equations, we will deal with two variable linear equations.

• Very similar but this time, the equation will have two variables

• Don’t panic, one variable will have a value!

HomeTOCHow to Solve linear equations with two variablesPractice solving linear equations with two variables

How To Solve Linear Equations With Two Variables• Step 1: plug in given value of one variable• Step 2: locate variable that needs to be solved for• Step 3: determine what arithmetic needs to be

done to solve for variable• Step 4: compute the arithmetic and find variable

• Home• TOC• Practice examples of two variable linear equations

Practice with Two Variable Linear Equations• X+7-y=10; y=2• Check Answer

• Y-4+z=5; z=3• Check Answer

• b+c-4=12; b=6 HOME• Check Answer

Answer• X=5

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Answer• Y=12

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Answer• C=10

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Practice Linear Equations with One Variable• X-6=4• Check Answer

• X+4=5• Check Answer

• Y-2=3• Check Answer

• 9-z=6• Check Answer

• 7+p=10 TOC• Check Answer

Answer• X=10

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Answer• X=1

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Answer• Y=5

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Answer• Z=3

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Answer• P=3

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