Question

(x+y)^2 + (x-y)^2 qual é o resultado???​

Answer 1

$(x+y)^2~+~(x-y)^2~=\\\\\\=~(x\,.\,x~+~x\,.\,y~+~y\,.\,x~+~y\,.\,y)~+~(x\,.\,x~+~x\,.\,(-y)~-~y\,.\,x~-~y\,.\,(-y))\\\\\\=~(x^2~+~xy~+~xy~+~y^2)~+~(x^2~-~xy~-~xy~+~y^2)\\\\\\=~x^2~+~2xy~+~y^2~+~x^2~-~2xy~+~y^2\\\\\\=~\boxed{2x^2~+~y^2}$