Упростите выражение (a + b)(a + 2) - (a - b)(a - 2) - 2ab

Question

Упростите выражение (a + b)(a + 2) - (a - b)(a - 2) - 2ab

Answer 1

(A+B)(A+2) = A²+2A+AB+2B
(A-B)(A-2)= A²-2A-AB+2B

A²+2A+AB+2B -(A²- 2A-AB-2B)= 4A+2AB+4B

4A+2AB+4B - 2AB= 4A+4B

Answer 2

 =a²+2a+ab+2b-(a²-2a-ab+2b)=a²+2a+ab+2b-a²+2a+ab-2b=4a+2ab