geometry/algebra question?

Question

A corner lot has dimensions 25 by 80 yards. The city plans to take a strip of uniform width along the two sides bordering the streets to widen these roads. How wide should the strip be if the remainder of the lot is to have an area of 921 square yards? Please label the unknown quantity as x.

Answer 1

(25-x)*(80-x) is the new area.

It's supposed to be 921.

Use the quadratic formula to get the actual answer.