\(4x-2y-4x^2+4xy-y^2\)
\(=\left(4x-2y\right)-\left(4x^2-4xy+y^2\right)\)
\(=2\left(2x-y\right)-\left(2x-y\right)^2\)
\(=\left(2x-y\right)\left(2-2x+y\right)\)
9: Ta có: \(4x-2y-4x^2+4xy-y^2\)
\(=2\left(2x-y\right)-\left(2x-y\right)^2\)
\(=\left(2x-y\right)\left(2-2x+y\right)\)