evaluating expressions

Multiple Choice

What is a variable? 

• A number such as x that represents an un specified number

• a number that varies or changes throughout a problem

• A number

• a letter

Evaluating Expressions

Solve by substituting the variable with the value

evaluate:

2x + 4y

x = 5

y = 2

replace the variable:

2 (5) + 4 (2)

Solve:

10 + 8 = 18

Multiple Choice

Evaluate 2a + 4b 
if a = 10     and    b = 6

• 20

• 24

• 44

• 4

Multiple Choice

What is 4x if x=5?

• 20

• 16

• 9

• 45

Evaluating Expressions

Solve in the parentheses first, then order of operations

replace the variable:

2(3 + 4) + 6

Solve:

2(7) + 6

14 + 6 = 20

evaluate:

2(x + 4) + 6

x = 3

Multiple Choice

Evaluate when a = 15:
2(a - 5) + 2

• 22

• 27

• 14

• 7

Multiple Choice

What is 3x+(5+y) if x=2 and y=7?

• 18

• 28

• 8

• 3

Multiple Choice

b² + 4
when b = 3

• 10

• 12

• 13

• 11

Multiple Choice

What is 6+x when x=53?

• 59

• 50

• 47

• 90642

Multiple Choice

Evaluate the expression.   Let g = 3    h = 9 
4h + 2g + 4

• 42

• 46

• 34

• 58

Multiple Choice

Evaluate x ÷ 4 if x = 80

• 4

• 20

• 40

• 80

Multiple Choice

Evaluate 3d if d = 5

• 3

• 5

• 12

• 15

Multiple Choice

Evaluate 5m + 7 if m = 5

• 12

• 25

• 32

Multiple Choice

What is  x-14(5+y) when x=13 and y=14

• -19

• 19

• Impossible 

• 16

Multiple Choice

Evaluate c² - 11 if c = 8

• 64

• 63

• 54

• 53

Multiple Choice

Evaluate m - n if m = 29 and n = 11

• 29

• 28

• 19

• 18

Multiple Choice

what is x•x when x=16

• 256

• 32

• 1

• 16

Multiple Choice

Evaluate 4w - 3y if w = 7 and y = 6

• 24

• 21

• 10

• 46

Multiple Choice

$$Evaluate\ 4c\ +\left(4d\ +3\right)^2\ for\ c=2\ and\ d=1$$  

• 21

• 57

• 225

• 125

Multiple Choice

$$Evaluate\ 9-\left(\frac{8}{a}+3\right)\ for\ a\ =2$$  

• 2

• 8

• $$7\frac{2}{5}$$  

• -4