Combine Like Terms

9x + 8x

• 72x

• 1x

• 17x

• -1x

x + 1 + 3x

• 3x + 1

• 4x + 1

• 3x + 4

• 5x + 3

4x - 3 + 2 - 2x

• 6x + 5

• 2x + 1

• 2x - 1

• 6x - 1

Simplify the expression: 2x + 1 + 7x 

• 10x
• 10
• 9x + 1
• 9 + 1x

a + a + a + a

• a + 4 
• 4a 
• a to the fourth power 
• 4a + 4 

How many terms are in the expression
3a + 2b + c + 100

• 3
• 4
• 5
• 6