Question

Simplify: (2a+3b)²-(2a-3b)² + 12 ab​

Answer 1

6b × 4a + 12ab

24ab + 12ab

36ab

Answer 2

(a+b)²=a²+2ab+b²

(2a+3b)= (2a)²+2×2a×(3b)²=4a²+4a×9b²=4a²+36ab²

(a-b)² = a²-2ab+b²

(2a+3b)²= (2a)²-2×2a×(3b)²=4a²-4a×9b²

=4a²-36ab²

4a²+36ab²-4a²-36ab²+12ab = 12ab

is the answer