(f ° g) (x) means the composition of the two functions in this order f (g (x) )
So, given f(x) = - 9x + 9 and g(x) = √(x + 1), you must do this:
f(g(x)) = - 9 [ g(x) ] + 9 = - 9 [√(x+1) ] + 9 => f(g(24) = - 9 √(24 + 1) + 9 = - 9√25 + 9 =
= -9(5) + 9 = -45 + 9 = - 36
Answer: - 36