Question 30439
f(x)=x+1----(1)and 
g(x)=2x ----(2)
To find  1)f(g(x)) and 2)g(f(x))
1)f(g(x)) = f(2x)(using (2)
=f(t) where t = 2x ----(*)
=t+1 using (1)
=2x+1

2)g(f(x))
=g(x+1) using(1)
=g(u) where u = (x+1)----(**)
=2u  using (2)
=2(x+1) using (**)

Answer: f(g(x))=2x+1
and  g(f(x))=2(x+1)