This is volume of a sphere.
Answer:
combine -3-1

if you want to solve for x then you would move the -14 to the left buy adding 14 to both sides.

your equation there will be

then you will divide -2 on both sides

finally x will equal

6 / 8 = 3/4
3/4 x 7 = 5 1/4
5 1/4 = $5.25
So, 7/8 of a pound of shrimp costs $5.25.
Pretty sure that you got it right..