Question

X minus Y the whole square minus X plus Y the whole square

Answer 1

Answer:

$= (x - y) {}^{2} +( x + y) {}^{2} \\ = x {}^{2} + y {}^{2} - 2xy + x {}^{2} + y {}^{2} + 2xy \\ = 2x {}^{2} + 2y {}^{2}$