Question 298322
solve 27x^3+216=(3x+y)(9x^2-18x+36) for y
factor
27*(x^3+8)=27*(x+2)*(x^2-2 x+4)
(9x^2-18x+36) =9*(x^-2x+4)

27*(x+2)*(x^2-2x+4) = 9*(x^2-2x+4)*(3x+y)
27/9=3

which you can see can be reduced to
3(x+2)=3x+y
3x+6=3x+y
6=y