Use the five steps for problem sovling.
Christy’s plan for a rectangular dog pen is too small. The perimeter needs to be more than 118 feet. If the width should be nine feet shorter than the length, what should the length be?
2 w + 2 L =118
L = w + 9
2 w + 2(w+9) = 118
4 w + 18 = 118
4 w = 100
w = 25
L = 36
so L > 36