Question

[quan Nguyen tran dinh]

(x+y)²+(x-y)²

cac ban de lai cach giai voi va giai theo hang dang thuc tks

Answer 1

[Hoàng Lê Bảo Ngọc]

\(\left(x+y\right)^2+\left(x-y\right)^2=\left(x^2+2xy+y^2\right)+\left(x^2-2xy+y^2\right)=2\left(x^2+y^2\right)\)

Answer 2

[Nguyễn Tuấn Tài]

(x+y)²+(x-y)² = ( x² +2xy+y² ) + (x² -2xy+y² ) =\(2\left(x+y\right)^2\)