Mn giải giúp e vs ạ!!!

`\color{lightblue}{Answer}`

a) `5x^2-10x=5x(x-2)`

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

c) `4x^2-4xy-8y^2=(2x)^2-4xy+y^2-9y^2=(2x-y)^2-(3y)^2=(2x-4y)(2x+2y)`

`\color{white}{Gts}`