Unit 7: Expressions Study Guide

Writing Expressions

100

8 less than a number

x - 8

200

10 less than twice a number

2x - 10

300

14 more than 8 times a number

8x + 14

400

3 times the sum of 13 and a number

3(13 + x)

Distribution

100

4(x + 2)

4x + 8

200

12(2x + 3)

24x + 36

300

Simplify COMPLETELY: 8(2x + 4x)

16x + 32x

400

Simplify COMPLETELY: 3(5x - 2x)

9x

Combining Like Terms

100

3x + 5 - 2x - 3

x + 2

200

4y² + 2x + 5y² + 3x

9y² + 5x

300

4x² + 5x² + 6y - 4y - x²

8x² + 2y

400

6x² - 6x + 3x² + 10x

3x² + 4x

Substitution

100

2x + y if x = 2 and y = 4

8

200

8x² + 2y if x = 2 and y = 5

42

300

3x² + 2y² if x = 3 and y = 4

59

400

9x³ - 2x + y² if x = 2 and y = 7

117

PEMDAS

100

Simplify: 2 x 4 + 8

16

200

Simplify: 3(4 + 8) - 3

33

300

Simplify: 4(3 + 4) + 5² - 4

49

400

Simplify: 4(3)² - 4 + 5 x 9

77