Question

(x-y)^2+(x+y)^2=2 (x^2+y^2

Answer 1

x^2-2xy+y^2+x^2+2xy+y^2=2x^2+2y^2
2x^2+2y^2=2x^2+2y^2
2x^2-2x^2=2y^2-2y^2
0=0
ответ:0