Your answer should be D, 163, hope this helps! :D
Given :
The foci of hyperbola are (8,0) and (-8,0) .
The difference of the focal radii = 6.
To Find :
The equation of the hyperbola.
Solution :
We know, distance between foci is given by :
2c = 8 - (-8)
c = 8
Also, difference between the foci or focal distance is given by :
2a = 6
a = 3
Now, we know for hyperbola :

General equation of hyperbola is :

Hence, this is the required solution.
Answer:
C≈157.08in
Step-by-step explanation:
C=2πr=2·π·25≈157.07963in
90 x 7 = 630 square feet total
0.5 fluid ounce per sq ft
630 x 0.5 = 315 fluid ounces are needed
Slope = 1/2 :)
rise over run (rise/run)
so... 2/4 = 1/2
hope this helps!