Đáp án + Giải thích các bước giải:
`c)` `(x+y)(2x-y)+(2x-y)(3x-y)-(y-2x)`
`=(x+y)(2x-y)+(2x-y)(3x-y)+(2x-y)`
`=(2x-y)(x+y+3x-y+1)`
`=(2x-y)(4x+1)`
`d)` `ab^3c^2-a^2b^2c^2+ab^2c^3-a^2bc^3`
`=abc^2(b^2-ab+bc-ac)`
`=abc^2[b(b-a)+c(b-a)]`
`=abc^2(b-a)(b+c)`
`e)` `x^2(y-z)+y^2(z-x)+z^2(x-y)`
`=x^2(y-z)+y^2z-xy^2+xz^2-yz^2`
`=x^2(y-z)+(y^2z-yz^2)-(xy^2-xz^2)`
`=x^2(y-z)+yz(y-z)-x(y^2-z^2)`
`=x^2(y-z)+yz(y-z)-x(y-z)(y+z)`
`=(y-z)[x^2+yz-x(y+z)]`
`=(y-z)(x^2+yz-xy-xz)`
`=(y-z)[x(x-y) + z(y-x)]`
`=(y-z)[x(x-y)-z(x-y)]`
`=(y-z)(x-z)(x-y)`.
