Question

Simplify (a+2b+3c)^2- (a-2b-3c)^2-6b^2-9bc

Answer 1

(a+2b+3c+a-2b-3c)(a+2b+3c-a+2b+6c)-3b(2b+3c){a^2-b^2 = (a+b)(a-b)}
=(2a)(2b+6c)-3b(2b+3c)
=4ab+12ac-3b(2b+3c)
=4a(b+3c)-3b(2b+3c)

Answer 2

Answer:

Step-by-step explanation:

Hi there

(a+2b+3c+a-2b-3c)(a+2b+3c-a+2b+6c)-3b(2b+3c){a^2-b^2 = (a+b)(a-b)}

=(2a)(2b+6c)-3b(2b+3c)

=4ab+12ac-3b(2b+3c)

=4a(b+3c)-3b(2b+3c)