Answer: Hi!
Answers B and D are correct.
For B, since negative numbers are on the left side of the number line, a positive number would have to be to the right of a negative number. Since we are adding a negative and a positive number of the same absolute value (9), they would cancel out to 0, which makes D true.
Hope this helps!
This is an ellipse.
Equation of an ellipse: 
Let's find the center point first. We can do this by finding out the midpoint between the vertices or the foci.
(-9+7)/2=-1
Center: (-1,3)
Now we need to find a and b (length along x and length along y).
We know "a". It is the distance between the center and the right or left bound.
a=7-(-1)=8
To find out "b", first see that...
b^2=a^2-(distance from center to foci)^2
foci distance=3-(-1)=4
b^2=8^2-4^2
b^2=64-16
b^2=48
b=4√3
answer: 
D. the total quantity of shoppers are needed for statistical information
Instantaneous rate of change = S'(r) = 8πr
S'(8) = 8π(8) = 64π
Therefore, the instantaneoud rate of change of the <span>surface area with respect to the radius r at r = 8</span> is 64π