John is 5ft tall and is standing in the light of a 15ft lamppost. His shadow is 4ft long. He walks 1ft father away from the lamppost, by how many feet will his shadow lengthen?

This is a rational expression because the denominator contains a variable. this is a polynomial with 3 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 4 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 4 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 3 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 5 terms.