So we have the following system of equations:

We need to solve it by substitution. This means that we have to take the expression for x given by the second equation and replace x with it in the first equation:

So y=-1. If we use this value in the second equation:

So we have x=2 and y=-1 which means that there's one solution. Then the correct answer is A and the solution is (2,-1).
Step-by-step explanation:
The given function is :

(a) To find f(9), put x = 9 in the above expression.

(b) To find f(x+7), put x = x+7 in the above expression.

(c) To find f(-x), put x = -x in the above expression.

Hence, this is the required solution.
Answer:
m = 0.75
Step-by-step explanation:
16 x 2m = 4x8 - 8
32m = 24
m = 24/32