How do the squares of sums and differences relate?

Answer 1

(a + b) = a^2 + 2ab + b^2

(a - b)^2 = a^2 - 2ab + b^2 or you can work like this:

[a + (-b)]^2 = a^2 + 2a(-b) + (-b)^2

(a - b)^2 = a^2 - 2ab + b^2