Evaluating Variable Expressions

Order of operations

100

What does "PEMDAS" stand for?

P = parentheses E = exponents M = multiplication D = division A = addition S = subtraction

200

What does 8^2 (8 to the power of 2) mean?

8 times itself, or 8*8, or 64.

300

In the expression 9 x 3 - (7 + 9), which step should we start with according to PEMDAS?

7+ 9 = 16

400

Solve: 5(4² + 3)

5(16 + 3) = 5*19 = 95

500

(3² + ( 6 / 2 + 7²)) + 4²

95

Evaluate algebraic expressions

100

3(y + x) ; use x = 4, y = 0

3(4) = 12

200

4 + xy ; use x = 7 and y = 3

4 + 21 = 25

300

8(5 - x) - y ; use x = 3 and y = 12

8(5 - 3) - 12 = 8(2) - 12 = 16 - 12 = 4

400

(c + d) + 4(c) ; use c = 8, d = 9

(8 + 9) - 4(8) = 17 + 32 = 49

500

5(f - h) - 2h ; use h = –1, f = 2

5(2 - -1) - 2(-1) = 5(2 + 1) + 2 = 5(3) + 2 = 17

Combine Like Terms

100

4x + 2x + 7x

13x

200

5y + 7x + 3 + 4x + 2

5y + 11x + 5

300

10x + 4y + 3b + 2x – 2y

3b + 12x + 2y

400

5x + 3y - 4x + 4y + 3z²

x + 7y + 3z²

500

3a² + 2b + 9a - 4a + 4a² + 16

7a² + 2b + 5a +16

Exponents

100

What is 2²?

4

200

What is 3³?

27

300

x⁴ ; use x = 3

81

400

x(y²) ; use x = 3, y = 5

75

500

y(y ³) + x ; use x = 3, y = 2

19

Vocabulary

100

A number is called what?

A constant

200

A letter of the alphabet that represents an unknown number is called what?

variable 

300

a set of numbers or letters separated by operations is called what?

term

400

terms that have the same variable raised to the same power is called what?

Like terms

500

a number in front of a variable is called what?

coefficient