I need help with a precalc project. area, volume, inequalities, etc. i can email scans to anyone who thinks they can help. thanks.

heres the question

you are putting in a 20ftx30ft rectangular pool. your pool must be surrounded by a concrete sidewalk of uniform width and 3in thick.

write an expression in terms of x to represent the volume of concrete contained in the sidewalk. explain how you got your expression.