Chapter 7 Solving Two-Step Equations Algebra Concepts Chapter 7 Solving Two-Step Equations

When you solve for the variable in an equation, you “unwrap” the variable You want the variable alone on one side of the equation.

Wrapping/Unwrapping a Gift #1 Put item in box #2 Put lid on the box #3 Wrap box in paper #4 Put a bow on the box #1 Take bow off the box #2 Take paper off the box #3 Take lid off the box #4 Take item out.

Steps are in reverse order Steps are opposite operations

Addition↔Subtraction Multiplication↔𝐃𝐢𝐯𝐢𝐬𝐢𝐨𝐧 The reverse order of operations is S A D M E P Opposite Math Operations Addition↔Subtraction Multiplication↔𝐃𝐢𝐯𝐢𝐬𝐢𝐨𝐧

Solve for x 2𝑥−5=7 +5 +5 2𝑥 = 12 ÷2 ÷2 𝑥 = 6

What you do to one side of the equation, you __________________________. Follow this pattern Do something, do something Write a new equation

This is like peeling off the layers of an onion.

2 3 𝑐+1=5 −1 −1 2 3 𝑐 =4 ∙ 3 2 ∙ 3 2 𝑐 = 6

Another way to think about this! If you have two friends and you can only take one on a trip with you, who do you keep the close friend or the not so close friend?

close friend not-so-close friend Solve for x. 4𝑥+3=18 close friend not-so-close friend So get rid of the 3 first!

Be careful! Solve for x 7−𝑥=10 Do something #1 −7 −7 What is the new equation?

Try these. #1 4𝑥−5=11 #2 18=3𝑥+3 #3 −2𝑥+9=−15 #4 15=6−𝑥 #5 𝑥 3 +4=0

Mike has $42 saved and is saving $15 a week to buy a sport jersey Mike has $42 saved and is saving $15 a week to buy a sport jersey. The jersey costs $147 (including tax) How many weeks (w) will it take to have enough money to buy the jersey?

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