Question

simplify (3a+3b)^2-2a-2b-1

Answer 1

use
(a+b)^2=a2+b2+2ab
simply open this square and get result.

Answer 2

you can actually factor out a 3 then apply the formula shown above before grouping like terms to simplify

Answer 3

(3a+3b)^2 =[3(a + b)}^2 = 3^2*(a + b)^2
=9(a^2 + 2ab + b^2) = 9a^2 + 18ab + 9b^2
so (3a+3b)^2-2a-2b-1 = 9a^2 + 18ab + 9b^2 -2a -2b -1

another approach would be to use the difference of 2 squares