The answer actually is 4,245 BUT that is the correct way to do it because you take the smaller population away from the larger population in order to find their difference in sizes.
Answer:
A. 
Step-by-step explanation:
The options are:

For this exercise it is important to remember that, by definition, the Exponential parent functions have the form shown below:

Where "a" is the base.
There are several transformations for a function f(x), some of those transformations are shown below:
1. If
and
, then the function is stretched vertically by a factor of "b".
2. If
and
, then the function is compressed vertically by a factor of "b"
Therefore, based on the information given above, you can identify that the function that represents a vertical stretch of an Exponential function, is the one given in the Option A. This is:

Where the factor is:

And 
Answer:
t = 3
Step-by-step explanation:
Given
- 3 (t - 2) + 7t = 9t - 9 ← distribute left side and simplify
- 3t + 6 + 7t = 9t - 9
4t + 6 = 9t - 9 ( subtract 9t from both sides )
- 5t + 6 = - 9 ( subtract 6 from both sides )
- 5t = - 15 ( divide both sides by - 5 )
t = 3
It is convenient to do part b first, then use that result to do part a.
b. For some pair of points (x1, y1) and (x2, y2), you want to find a point (a, b) such that (a, b) - (x1, y1) = (x2, y2) - (a, b). That is, the differences of coordinates from one end to the center are the same as the differences from the center to the other end.
Adding (a, b) to the above equation gives
2(a, b) - (x1, y1) = (x2, y2)
Adding (x1, y1) then gives
2(a, b) = (x1, y1) + (x2, y2)
Finally, dividing by 2 gives a formula for (a, b):
(a, b) = ((x1, y1) + (x2, y2))/2
The midpoint is the average of the end points.
a. Using the result from part b, the midpoint is
midpoint = ((2, 3) + (6, 7))/2 = (8, 10)/2
midpoint = (4, 5)