Looks OK, but the second term is really hard to fathom.
If you're using Word or something similar, your exponents like (4/5) need to have braces -- { } -- around them.
In LaTeX, and cleaned up a bit by making both expressions involve exponents, and getting rid of unneeded parentheses, your answer looks like this:
$$\frac{dy}{dx} = 3(x - 1)^2 (2x^2 - 1)^{1/5} + \frac{4x(x - 1)^3}{5(2x^2 - 1)^{4/5}} $$