\(xy\left(x+y\right)-y\left(x+y\right)^2+y^2\left(x-y\right)\)\(=\left(x+y\right)\left(xy-xy-y^2\right)+y^2\left(x-y\right)\)\(=-y^2\left(x+y\right)+y^2\left(x-y\right)\)\(=y^2\left(-x-y+x-y\right)\)\(=-2y^3\)Câu trả lời: \(xy\left(x+y\right)-y\left(x+y\right)^2+y^2\left(x-y\right)\)\(=\left(x+y\right)\left(xy-xy-y^2\right)+y^2\left(x-y\right)\)\(=-y^2\left(x+y\right)+y^2\left(x-y\right)\)\(=y^2\left(-x-y+x-y\right)\)\(=-2y^3\)