Answer:
4x -51
Step-by-step explanation:
m(n(x)) = m(x - 10) = 4(x-10) - 11 = 4x -40 -11 = 4x -51
13 3/39 is too big, it's greater than 9, so that one is out.
16 is an integer, so that one is out too. 99/6 = 16.5, which is greater than 9, so it can't be right
So the answer is the other 3
It's most likely the first or 3rd answer. Apologies If I'm wrong.