posted by tyler .
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.
If x is the width in feet, the volume in cubic feet is
[(30 + 2x)(20 + 2x)- 30*20]*(1/4)
That expression can be simplified somewhat by canceling out the 600's.