Question

(a+b)(a+b+2)-(a-b)(a-b-2)

Answer 1

1)(a+b)*(a+b+2)=a²+ab+2a+ab+b²+2b=a²+2ab+b²+2a+2b
2)(a-b)(a-b-2)=a²-ab-2a-ab+b²+2b
3)a²+2ab+b²+2a+2b-a²-2ab-2a+b²+2b=2b²+4b=2b(b+2)