hi guys can you please help me with this:

Find f given that f''=$\displaystyle \frac{-3}{x^2} $,f'(3) =5, and f(1) =3.I got this far:

f'= $\displaystyle \frac{3}{x} + 4$

f=3log(x)+ 4x + C = 3

so log((1)^3) + 4(1) + C =3

Am I on the right track? If so I don't quite know what to do next