Hello all,

What would be the easiest way to simplify a polynomial raised to a fractional power. Such as this:

(40 + 2x)^(-2/3)

And here is the main problem:

I'm trying to solve for x in this equation:

821.6 = (40x)^(5/3) * (40 + 2x)^(-2/3)

All help is appreciated. Thank you.