I have f(x)=$\displaystyle \frac{8}{x^3}-\frac{7}{x^7}$ and I want to find F(x)

I am also given that F(1)=0

I get F(x)=$\displaystyle \frac{7}{6x^6}-\frac{4}{x^2}+C$

and since F(1)=0

F(x)=$\displaystyle \frac{7}{6*(1)^6}-\frac{4}{(1)^2}+C=0$

F(x)=$\displaystyle \frac{7}{6}-4+C=0$

F(x)=$\displaystyle -17/6+C=0$

so c=17/6

however the above is wrong somewhere. I just don't see where