your fractions don't make any sense.
is dangerous.
See its result:
integrate 1/(3z^3+7) - Wolfram|Alpha
But you can do it as an infinite series.
Oh thats nasty. I dont think I should know how to do anything like that. Im trying to solve dy/dx = (7X - 3Y)^3
And i used the substitution Z = 7X - 3Y
and i come up with that integral
Edit: I ended up with A SIMPLE ODE and i was treating it as variable seperable I think this was the problem