Question

If (3a + 3b + 1) (3a + 3b - 1) = 80, then what is a + b?

Answer 1

Answer: a + b = 3 -        maybe

Step-by-step explanation:

( 3a + 3b + 1 )( 3a + 3b - 1 ) = 80

Expand

9a² + 9ab - 3a + 9ab + 9b² - 3b + 3a + 3b - 1 = 80

Simplify

9a² + 9b² + 18ab - 1 = 80

move the 1 over

9a² + 9b² + 18ab = 81

divide by 9

a² + b² + 2ab = 9

not really sure after this part

move the 2ab over

a² + b² = 9 - 2ab

square root both sides

a + b =  

simplify

a + b = 3 -