a pyramid has height x cm and a square base whose edges are 3 cm less than twice the height. Find the volume.
Height = x and base edge (side) = 2x - 3...so we have....
Volume = (1/3)*(area of the base) *(height) = (1/3)*(side)^2*(height)=(1/3)*(2x -3)^2*(x) =
(1/3)*((2x -3)*(2x -3)* x = (1/3)*(4x^2 - 12x + 9)*x = [4x^3 - 12x^2 + 9x] /3 cubic units