Me
let f(x)=x^2+5 and g(x)= (x+5)/5 . find (g o ).

                  

First find gf(x) by substituting the expression for f(x) wherever there is an x in the g(x) function 



Simplify the equation and then substitute -3 where the x's are in gf(x)

gf(x) =  

gf(-3)  =  
          
           =  
 
           =  

Keen to note that if you worked f(-3) first and then substituted that into g(x) then you would get the same answer.

Add up all the sides