All you need to do is trace the given X value to the graph of the function after 'o' in (fog) or (gof). This is the same as finding the value of f(x) or g(x). After finding the value, make that value your x and trace to the new value on the other graph
a) Tracing -1 to y = f(X) gives y= 3. Tracing x =3 to g(x) gives 2
