Variable:Is a quantity that can change or vary. Mathematicians use variables (letters) to represent numbers.

Constant:A quantity that does not change.

5w + 18

Expression:Is a mathematical phrase involving constants, variables, and operation symbols.

Evaluate each expression for x=1, 2, and 3.

x x + 5

1 1 + 5 = 6

2 2 + 5 = 7

3 3 + 5 = 8

m m + 10

2 2 + 10 = 12

5 5 + 10 = 15

11 11 + 10 = 21

Evaluate each expression

x 4x + 8

6 4(6) + 8 = 32

10 4(10) + 8 = 48

12 4(12) + 8 = 56

Evaluate each expression

p 12 ÷ p + 2p

2 12 ÷ 2 + 2(2)6 + 2(2)

6 + 410

4 12 ÷ 4 + 2(4)3 + 2(4)

3 + 811

6 12 ÷ 6 + 2(6)2 + 2(6)2 + 12

14

Evaluate each expression

c c² + 9 5c + 2 2 • c • 4

5 52 + 925 + 9

34

5(5) + 225 + 2

27

2(5)(4)10(4)

40

7 72 + 949 + 9

58

5(7) +235 + 2

37

2(7)(4)14(4)

56

10 102 + 9100 + 9

109

5(10) + 250 + 2

52

2(10)(4)20(4)

80

Evaluate each expression

x = 3 y = 12 z = 8 SHOW ALL WORK

4z + 8 – 6 4(8) + 8 – 6 = 376x – 9 ÷ 3 6(3) – 9 ÷ 3 = 615 + 9x ÷ 3 15 + 9(3) ÷ 3 = 247z ÷ 4 + 5x 7(8) ÷ 4 + 5(3) = 29y2 ÷ 3x 122 ÷ 3(3) = 16