7th Grade Math

Multi-Step Equations

PART A B C

Multi-Part

Lesson 3

Get ConnectED

DE

GLE 0706.3.8

Use a variety of strategies

to efficiently solve linear

equations and inequalities.

Also addresses GLE 0706.1.4,

GLE 0706.1.8.

Equations with

Variables on Each Side

Some equations have variables on each side of the equals sign.

Solve x + 5 = 2 x + 2 using algebra tiles.

Model the equation.

x = x x

1

1

1

1

1

1

1

x + 5 = 2 x + 2

Remove one x-tile

x x

1

1

x =

x - x + 5 = 2 x - x + 2

1

1

1

1

from each side of 1

the mat. All of the

x-tiles are on one

side of the mat.

Now you can

x

1

1

1

1

1

1

1

=

3 = x

remove two

1-tiles from each

side. There are

3 tiles on the left

side of the mat.

The solution is 3.

the Results

Use algebra tiles to model and solve each equation.

1. 3 x - 2 = 2 x + 1 2. 2 x + 6 = 4 x - 2


2. x + 1 = 3 x - 3 4. 2 x - 9 = 5 x + 3


3. Does it matter whether you remove x-tiles or 1-tiles first? Explain.


4. What property of equality allows you to remove an x-tile from
   each side of the mat?

Main Idea

Use algebra tiles to

solve equations with

variables on each side

of the equation.

Lesson 3C Multi-Step Equations 235

228_239_C04L3_895130.indd 235 12/31/09 4:00 PM