Hello!
First, let's rewrite the functions below:
[tex]\begin{gathered} g(x)=0.90x \\ f(x)=0.13x \end{gathered}[/tex]
alternative A.
We can write it as a composite of 2 functions, look:
[tex]\begin{gathered} f(g(x))=0.13\cdot(0.90x) \\ f(g(x))=0.117x \end{gathered}[/tex]
alternative B.
First we have to calculate the 10% of discount using the function:
[tex]\begin{gathered} g(x)=0.90x \\ g(39.99)=0.90\cdot(39.99) \\ g(39.99)\approx35.99 \end{gathered}[/tex]
Then, we have to use the other function f(x):
[tex]\begin{gathered} f(x)=0.13x \\ f(35.99)=0.13\cdot(35.99) \\ f(35.99)\approx4.68 \end{gathered}[/tex]
Answers:
a. 35.99
b. 4.68
