Well first you need to show the rest of the problems before i can truely help you sorry.
Answer:
D) -122
Step-by-step explanation:
Given:

We need to find f(-4).
Now by substituting the value of x =-4 in above equation we get;

By using PEDMAS we will solve for exponential function first we get;
Now we know that 
So we get;

Now using PEDMAS we will solve division.

Now using PEDMAS we solve multiplication.

Finally by subtraction we get;

Answer: They are inverses of each other
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Explanation:
We'll need to compute h(f(x)) and f(h(x)) to see if we get x each time.

and,

Both composite functions lead to x each time.
The equations h(f(x)) = x and f(h(x)) = x being true means each function is the inverse of the other.
Answer:
Bob forgot to distribute 3 to 1.50 in the parentheses
Step-by-step explanation:
Bob made the mistake in his first step.
In the equation 3(x + 1.50) = 30, the 3 has to be distributed to both x and 1.50.
But, Bob only distributed it to x, which led him to get the wrong answer.
So, Bob's mistake when solving was that he forgot to distribute the 3 to 1.50