Simplify It!
Work Backwards
Equivalent Expressions: True or False
Find the Error
Build an Equivalent Expression
200

Simplify:

9x - 4x + 7

5x + 7

200

Fill-in the blank:

7x + 14 = 7(____ + 2)

x

200

Is 5x + 2x = 7x ?

True, Combine Like Terms

200

A student says 3x + 4x = 12x.  What is the error, and the correct answer?

They multiplied the coefficients instead of adding them. Correct answer is 7x.

200

Simplify: x + x + x + 6

3x + 6

400

Simplify:

3a + 5 - 2a + 8

a + 13

400

Fill-in the blank:

4(x + 3) = 4x + _____

12

400

Is 

3(x + 4) = 3x + 4 ?

False, it equals 3x + 12.

400

A student expands 5(2x - 3) as 10x - 3.  What is the error and correct answer?

They didn't distribute 5 and -3.  The correct answer is 10x - 15.

400

Factor into Distributive Property Form: 4x + 20

4(x + 5)

600

Simplify:

6(3x - 2) - 2(4x + 1) 

10x - 14

600

What number belongs in the blank?

3(2x + ____) = 6x + 15

5

600

Is 

2(3x + 5) - x = 5x + 10 ?

True, both simplify to 5x + 10.

600

A student simplifies 2x + 3 + 4x + 5 to 6x + 8x.  Explain the mistake and what is the correct answer?

They combined unlike terms.  The correct expression is 6x + 8.

600

Factor into Distributive Property: 6x - 9.

3(2x - 3)

800

Simplify:

5 (2x - 3) - 3(x + 4) + 2x

9x - 27

800

Find A:

5(x + 2) + A = 8x + 10

A = 3x

800

Is 

4(x + 2) + 3x = 7(x + 2) ?

False, the left side is 7x + 8; the right side is 7x + 14.

800
A student expands -3(2x - 5) as -6x - 15.  What is the error and the correct answer?

Didn't follow sign rules for multiplying -3 and -5 .  The correct answer is -6x + 15.

800

Simplify: 5(x + 2) + 2x.

7x + 10

1000

Simplify:

4(2x + 3) - 5x

3x + 12

1000

Find an expression for A:

4(2x - 3) + A = 11x + 1

A = 3x + 13

1000

Is 2(3x - 4) + 5 = 6x - 3 equivalent to 3(2x - 1) - 2  ?

True, both simplify to 6x - 3.

1000
A student claims 2(4x - 3) - 3(x + 2) = 5x.  What is the error and the correct answer?

They omitted the constant terms.  The correct answer is 8x - 6 - 3x - 6 = 5x - 12.

1000
Rewrite as an addition expression:

-6x - 3

-6x + (-3)