What is the width of the tank?

Question

A tank is 4 feet longer than its width. The height is 2 feet more than the width. The volume of the tank is 105 cubic feet.

Answer 1

width = w

length= w+4

height= w+2

volume=w*l*h

w*w+2*w+4=105

w^2+2w*w+4=105

w^3+4w^2+2w^2+8w=105

w^3+6w^2+8w=105

w=3