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;

Let the walker’s speed be W, then the biker’s is W+1.5W=2.5W. Difference in speed is 1.5W. Distance=speed times time, so 12.5=1.5W×1.5=2.25W, and W=12.5/2.25=1250/225=50/9=5.56 mph. The biker’s speed is 2.5W=125/9=13.89 mph to 2 Dec places.
(Note: “1.5 times faster than a walker’s speed” could not reasonably mean the biker’s speed=1.5W because this would give W=16.67 mph, which is very fast for a runner, let alone a walker (!), and a biker’s speed of 25mph.)
Answer:
munbers may be used once Or more than once