Expressions and Equations

ONE-STEP EQUATIONS

100

Solve:
x + 7 = 15

x=8

200

Solve:

x – 9 = 4

x=13

300

Solve:

5x = 45

x=9

400

Solve:

x ÷ 6 = 7

x=42

500

Solve: 

–12 = x – 20

x=8

TWO-STEP EQUATIONS

100

2x + 3 = 15

x=6

200

4x – 5 = 19

x=6

300

3x + 4 = 10

x=2

400

5(x – 2) = 25

X=7

500

3x + 8 = –10

x = –6

MATH VOCABULARY

100

What do you call a number multiplied by a variable?

Coefficient

200

What is a mathematical sentence that uses an equals sign?

Equation

300

What is a value that makes an equation true?

Solution

400

Two expressions that have the same value are called what?

Equivalent expressions

500

What do we call a number without a variable?

Constant

FIND THE ERROR

100

x + 5 = 12 → x = 17
What is the error?

They added instead of subtracting. x = 7

200

3x = 18 → x = 3
What is the error?

They divided by 3 wrong; x = 6

300

2x – 4 = 10 → 2x = 6 → x = 6
What is the error?

Added incorrectly; correct x = 7

400

4(x + 2) = 4x + 2 

What’s the error?

Didn’t distribute correctly; should be 4x + 8

500

3x + 4y =7xy
Error

Cannot combine unlike terms. Correct: 3x + 4y

EQUIVALENT EXPRESSIONS

100

Which is equivalent to 4(x + 1)?

4x + 4

200

Combine like terms:
5x + 3x

what is 8x

300

2(3x – 4)
 

6x – 8

400

7x + 2x + 5?

9x + 5

500

3(x – 2) + 2x

5x – 6