Question

How do you factor `-21x - 27x ^ { 2} + 27x ^ { 4}`?

Answer 1

`-27x(x^3+x+1)`

Explanation:

Rearrange it first.
`-27x^4-27x^2-21x`

Factor out a `-27x` from all terms.
`-27x(x^3+x+1)`

The cubic is not factorable.