Gary mails 10^3 flyers to clients in one week . how many flyers does gary mail?

He mails

           (10^3) x (the number of weeks he keeps it up)

of them.

Here, f(x) = √x+9
g(x) = 8x - 13

So, for f(g(x)), just put the value of function g(x) in the function f(x)

It would be: f(g(x)) = √8x - 13 + 9

f(g(x)) = √8x - 4

Now, Take √4 as a common factor:
f(g(x)) = √4(√2x - 1)
f(g(x)) = 2(√2x - 1)

In short, Your Answer would be: f(g(x)) = 2(√2x - 1)

Hope this helps!