Question

How is$(a-b)^2=(a+b)^2-4ab$

Answer 1

Answer:

Your answer is listed above.

Answer 2

$(a-b)^2=(a+b)^2-4ab \\ 4ab = (a + b) { }^{2} - (a - b) {}^{2} \\ a {}^{2} + b {}^{2} + 2ab - a {}^{2} - b {}^{2} + 2ab = 4ab \\ 4ab = 4ab$