Mình gửi bài ạ

\(a,x^2y+2xy=xy\left(x+2\right)\)
\(b,x^2-6x+6y-y^2\)
\(=\left(x^2-y^2\right)+\left(-6x+6y\right)\)
\(=\left(x-y\right)\left(x+y\right)-6\left(x-y\right)\)
\(=\left(x-y\right)\left(x+y-6\right)\)
\(c,x^2-4x+4-y^2\)
\(=\left(x^2-4x+4\right)-y^2\)
\(=\left(x-2\right)^2-y^2\)
\(=\left(x-2+y\right)\left(x-2-y\right)\)