I need help in solving this

When you have a function that has a constant taking place of where the variable usually goes, it basically means x =4.

l'm sure you can figure out the rest.

Thanks HSC  

Guest, your notation is not right.

 It should be

g(x)=2x^2-20x+53

find f(4)

And just like HSC said you now have to replace all the xes with 4s and find the answer :)

that is

f(4)=2*4^2-20*4+53 = ??