Question

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

Rút gọn

Answer 1

`(x+y)^2 -2(x+y)(x-y)+(x-y)^2`

\(=\left[\left(x+y\right)-\left(x-y\right)\right]^2\\ =\left(x+y-x+y\right)^2\\ =\left(2y\right)^2\\ =4y^2\)