Đáp án+Giải thích các bước giải:
`(x-2)(x^2+3x-1)`
`=x(x^2+3x-1)-2(x^2+3x-1)`
`=x^3+3x^2-x-2x^2-6x+2`
`=x^3+(3x^2-2x^2)-(x+6x)+2`
`=x^3+x^2-7x+2`
`(x+3)(2x^2+x-2)`
`=x(2x^2+x-2)+3(2x^2+x-2)`
`=2x^3+x^2-2x+6x^2+3x-6`
`=2x^3+(x^2+6x^2)+(3x-2x)-6`
`=2x^3+7x^2+x-6`
`(2x-y)(4x^2-2xy+y^2)`
`=2x(4x^2-2xy+y^2)-y(4x^2-2xy+y^2)`
`=8x^3-4x^2y+2xy^2-4x^2y+2xy^2-y^3`
`=8x^3-(4x^2y+4x^2y)+(2xy^2+2xy^2)-y^3`
`=8x^3-8x^2y+4xy^2-y^3`
