USE FACTORING, QUAD FORMULA, AND COMPLETE THE SQUARE!
Chris cuts half a rectangular lawn, 40m by 30m, by mowing strips
of equal width around the perimeter. Jonah cuts the small rectangle
left. How wide a strip does Chris cut so that they share the work equally?

Hi Rimi,

Suppose the strip that Chris cuts is W metres wide.

What is the area of the lawn?
What is the area that remains for Jonah?
What is W if the area that remains for Jonah is half the area of the entire lawn?

Harley

Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.