Question

If 2(a^2+b^2)=(a+b)^2 then,
>a+b=0,
>ab=0,
>a=b,
>2a=b

Answer 1

2·(a^2 + b^2) = (a + b)^2

2·a^2 + 2·b^2 = a^2 + 2·a·b + b^2

a^2 + b^2 = 2·a·b

a^2 - 2·a·b + b^2 = 0

(a - b)^2 = 0

a = b