Question

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

Answer 1

a+b = 4
`√(3)`

Explanation:

3(a + b)^2 = 81

(a + b)^2 = 27

a + b = sq rt 27

a + b =
`√(9)`·
`√(3)`

a + b = 3
`√(3)`