I depends if it is asking for miles to hours or hours to miles but, doing i would do hours to miles so it would be 270:6 which simplifies to 45:1
ANSWER:
r = 
Explaination:
Convert the given curve into the the polar form.
x = rcosθ
y = rsinθ
in f(x,y) = (x²-y²) - √(x²+y²) = 0
put the values of x & y in given curve equation.
We get at,
g(r,θ) = (r²cos²θ - r²sin²θ) - √(r²cos²θ + r²sin²θ) = 0
g(r,θ) = r²(cos²θ - sin²θ) - √r² = 0
We know that,
cos²θ - sin²θ = cos2θ
g(r,θ) = r²(cos2θ) - r = 0
Solve for r
Finally we get:
r = 
2880 cubic inches is the answer.
The solution exist for the given equation are
x=-2
and
x=11/3
To answer this you need to make simple thought experiment. Since the number of sales after time passes cannot go negative (note that rate at which copies are sold can drop over time but total number cannot) that means that you are adding number of sales at first hour and during first hour.
first option cannot be the answer because you are subtracting 100 copies to total number of sold copies which is not logical.
The answer is D) s(x) = 100 + 12(x-1)
after 1 hour (if you replace x with 1 in equation above) you will get 100 copies which matches conditions in the text.