Question

a resposta é: 1/ 2(x+y)​

Answer 1

Resposta:

$({x^2\over2}-xy+{y^2\over2})\div(x^2-y^2)(x-y)=\\ \\( {x^2-2xy+y^2\over2})\div(x+y)(x-y)(x-y)=\\ \\ {(x-y)^2\over2}\div(x+y)((x-y)^2=\\ \\ {(x-y)^2\over2}\times{1\over(x+y)(x-y)^2}=\\ \\ cancela~~(x-y)^2\\ \\E= {1\over2(x+y)}$