Đáp án+Giải thích các bước giải:
`a,[15.(x-y)^3+12.(y-x)^2-x+y]:(3y-3x) `
`=[15(x-y)^3+12(x-y)^2-(x-y)]:[-3(x-y)]`
`=[(x-y)[15(x-y)^2+12(x-y)-1]:(-3(x-y))`
`=-(15(x-y)^2+12(x-y)-1)/3`
`=-(15x^2-30x+15y^2+12x-12y-1)/3`
`b,[5.(x-2y)^4+(x-2y)^2+2y-x]:(x-2y)`
`=[5(x-2y)^4+(x-2y)^2-(x-2y)]:(x-2y)`
`=(x-2y)[5(x-2y)^3+(x-2y)-1)]:(x-2y)`
`=5(x-2y)^3+(x-2y)-1`
`=5x^3-30x^2y+60xy^2-40y^3+x-2y-1`
`c,[6.(x+y)^3-5.(x+y)^2+3.(x+y)]:(x+y)`
`=(x+y)[6(x+y)^2-5(x+y)+3)]:(x+y)`
`=6(x+y)^2-5(x+y)+3`
`=6x^2+12xy+6y^2-5x-5y+3`