Question

Reducir: (x+y)2+(x-y)2+(1+x)(1-x)1+(1+y)(1-y)-2

Answer 1

(x+y)2+(x-y)2+(1+x)(1-x)1+(1+y)(1-y)-2 = 2x+2y+2x-2y+1-x²+1-y²-2=4x+2-x²-y²

=-x²-y²+4x+2