Okay this one is easy all you gotta do is look at the decimal point and the place its at.
Answer: r=(-189)
first you subtract both sides by 8 and get -21=r/9
then you multiply 9 with each side and get -189 = r
you can check by rewriting the problem with -189 as r and solving the equation
The answer for the question is option 2
The volume of the shaded region is 1650 cubic feet.