`e)`
`2(x-1)^3-5(x-1)^2-(x-1)`
`=(x-1)[2(x-1)^2-5(x-1)-1]`
`=(x-1)[2(x^2-2x+1)-5x+5-1]`
`=(x-1)(2x^2-4x+2-5x+5-1)`
`=(x-1)(2x^2-9x+6)`
`f)`
`x(y-x)^3-y(x-y)^2+xy(x-y)`
`=x(y-x)^3-y(y-x)^2-xy(y-x)`
`=(y-x)[x(y-x)^2-y(y-x)-xy]`
`=(y-x)[x(y^2-2xy+x^2)-y^2+xy-xy]`
`=(y-x)(xy^2-2x^2y+x^3-y^2)`
`g)`
`xy(x+y)-2x-2y`
`=xy(x+y)-2(x+y)`
`=(x+y)(xy-2)`
`f)`
`x(x+y)^2-y(x+y)^2-y^2(x-y)`
`=[x(x+y)^2-y(x+y)^2]-y^2(x-y)`
`=(x+y)^2(x-y)-y^2(x-y)`
`=(x-y)[(x+y)^2-y^2]`
`=(x-y)(x+y-y)(x+y+y)`
`=x(x-y)(x+2y)`
