Question 1059229
That first expression which should really be written  {{{(f o g)(x)}}}, tells that g is the input of f.  This is function composition.  The function {{{(fog)(x)}}} means the function f is given the function g as its input.  The notation can be written also as  {{{f(g(x))}}}.


NOW you understand and know what to do!  Simplify the composition.