1) Ta có: \(x^2+xy-2x-2y\)
\(=x\left(x+y\right)-2\left(x+y\right)\)
\(=\left(x+y\right)\left(x-2\right)\)
2) Ta có: \(x^2-xy-2x+2y\)
\(=x\left(x-y\right)-2\left(x-y\right)\)
\(=\left(x-y\right)\left(x-2\right)\)
3) Ta có: \(x^2-xy+2x-2y\)
\(=x\left(x-y\right)+2\left(x-y\right)\)
\(=\left(x-y\right)\left(x+2\right)\)
4) Ta có: \(10ax-5ay+2x-y\)
\(=5a\left(2x-y\right)+\left(2x-y\right)\)
\(=\left(2x-y\right)\left(5a+1\right)\)
5) Ta có: \(10ax-5ay-2x+y\)
\(=5a\left(2x-y\right)-\left(2x-y\right)\)
\(=\left(2x-y\right)\left(5a-1\right)\)
8) Ta có: \(2x^2-6xy+5x-15y\)
\(=2x\left(x-3y\right)+5\left(x-3y\right)\)
\(=\left(x-3y\right)\left(2x+5\right)\)
