The area of a rectangular swimming pool is given by 4x^2+19x+12ft^2.One side length of the pool is given by 4x + 3 feet. What is an algebraic expression for the other side length of the pool?

divide

******_ x______+ 4___________
4x+3 | 4 x^2 + 19 x + 12
*******4 x^2 + 3 x
*******-----------------
*************** 16 x + 12
*************** 16 x + 12