For which values of x and y does (x + y)^2 equal x^2 + y^2? For which values of x and y does (x + y)^2 not equal x^2 + y^2?

Question

please explain with your answer

Answer 1

(x+y)^2 = x^2 + 2xy + y^2 which = x^2 + y^2 when 2xy=0

2xy = 0 when either x = 0 or y =0

if both x and y are not zero, then (x+y)^2 does not equal x^2 + y^2