Giải thích các bước giải:
a) `(x-3)(x^2+3x+9)+x(x+2)(2-x)=1`
`=>x^3-3^3+x(2^2-x^2)=1`
`=>x^3-27+4x-x^3=1`
`=>4x-27=1`
`=>4x=28=>x=7`
b) `(x+1)^3-(x-1)^3-6(x-1)^2=-10`
`=>x^3+3x^2+3x+1-x^3+3x^2-3x+1-6(x^2-2x+1)=-10`
`=>6x^2+1-6x^2+12x-6=-10`
`=>12x-5=-10`
`=>12x=-5=>x=-5/12`