Question

Expressão(x-y)²-(x+y)²:

Answer 1

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

$x^{2} -2xy+ y^{2}- x^{2} +2xy+ y^{2} => 2y^{2}$

$2y^{2}$