Combining Like Terms & Evaluating Expressions

​Combining Like Terms

How many bottles of water do you have?

How many burgers did you order?

How many bags of doritos did you get?

w= water

b=burger

d=doritos

Therefore we have 3w+2b+1d

Multiple Choice

Simplify by combining like terms:

$$7b-3b+4f$$  

• 
  

  $$10b+4f$$  

• $$8b$$  

• $$4b-4f$$
  

• $$4b+4f$$   

Multiple Choice

Combine Like Terms to write an equivalent expression:

3t + 7y + t + 3y

• 3t + 10y

• 4t + 4y

• 4t + 10y

Multiple Choice

Simplify by combining like terms:
4x² - 3x + 11 -2x

• 4x² - 5x + 11
• 11x + 11
• 16x² - 5x + 11
• 10x²

Multiple Choice

Simplify by combining like terms:

$$5a+2b-3a+4$$  

• $$8a+2b+4$$  

• $$2a+2b+4$$  

• $$8ab$$  

• $$4ab+4$$  

Multiple Choice

Rewrite the expression by combining like terms.
4x² – 2x² + 2y + 6y² – y + x²

• 3x² + 3xy + 6y
• 6y² + 2xy + 2x
• 7x² + 35x
• 3x² + 7y² + y

EVALUATING expressions

Evaluating an Expression

For our purposes, when we evaluate an expression, we will be looking at expressions with variables, and replacing those variables with a number, and then solving using BEDMAS.

EXAMPLE

Evaluate 2x + 5 for x = 4

We will replace the x with 4, and then evaluate the expression:

2(4) + 5 = 8 + 5 = 13

Note: 2x means 2 times x, so if we replace it with 4,
it would be 2 times 4.

EXAMPLE 2

Evaluate 3x - 2y for x = 2 and y = -3

Replace x and y with the values, and then solve. Don't forget BEDMAS!

3(2) - 2(-3)
= 6 - (-6)
= 6 + 6 = 12

Multiple Choice

What is the value of 3x when x = 4

• 3

• 4

• 7

• 12

Multiple Choice

What is the value of 2x - 5 when x = 3

• 1

• 3

• 5

• 7

Multiple Choice

What is the value of 3xy if x = 4 and y = -2

• 5

• -5

• 24

• -24

Multiple Choice

What is the value of -3a - 2bc if a = -2, b = 3, and c = -1

• -12
• 0
• 6

• 12

Multiple Choice

$$5\left(x+2\right)-4y\ \$$  

if x = -3 and y = 1

• -9

• 21

• 1

• -29

Multiple Choice

9a - ab + 5b    
if a = 2 and b = 7

• 37
• 67
• 39
• 32