Why not just use the '^' symbol to represent powers?. That's what it's for.

Anyway, there are various ways to tackle these. The Rational Root Theorem is always a choice if it's a toughy.

You can also break it up:

Break it up:

Group and factor:

Factor:

See?. What's in the parentheses is the same.

Now, the quadratic factors as well. Finish up.