As stated above using the chain rule will allow you to get this problem out.
i.e f '(x)=h '(x)*g '(h(x)).
Now if you are able to determine your h(x) and g(x) you will find the derivitive.
In my opinion this is the best way to approach the chain rule as it is quite clean and methodical.
e.g. differentiate f(x)=0.5*(20*x+5)^4 with respect to x
here you would assign: g(x)=0.5*x^4
therefore g '(x)= 2*x^3
h(x)=20*x+5
h '(x)=20
therfore f '(x)=20*2*(20*x+5)^3
=40*(20*x+5)^3.
apply this too your problem and it should come out.
btw this is my first post and i hope i havent given away too much or too little information.
