Let f(x)= 4x-1 and g(x)= x to the second power + 5

f(x)  = 4x - 1        g(x) = x^2 + 5

(f o g) (6) = 

f [ g(6)]

g(6)  = 6^2 + 5   = 41

f(41)  = 4(41)  - 1 =  164  - 1   =   163