Evaluating Expressions

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

What is 4x if x=5?

• 20
• 16
• 9
• 45

What is 6+x when x=53?

• 59
• 50
• 47
• 90642

Evaluate m² if m = 7

• 9

• 14

• 49

• 51

Evaluate 5m + 7 if m = 5

• 12

• 25

• 32

b² + 4
when b = 3

• 10
• 12
• 13
• 11

What is the difference between an expression and an equation

• Expressions have an equal sign and equations do not

• Equations have an equal sign and expressions do not

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

• 20
• 24
• 44
• 4

Evaluate when a = 15:
2(a - 5) + 2

• 22
• 27
• 14
• 7

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

• 42
• 46
• 34
• 58