SOLUTION: I need help solving this problem. The length of a rectangular sign is 3 feet longer than the width. If the sign has space for 40 square feet of advertising, find its length an

Algebra ->  Systems-of-equations -> SOLUTION: I need help solving this problem. The length of a rectangular sign is 3 feet longer than the width. If the sign has space for 40 square feet of advertising, find its length an      Log On


   



Question 15912: I need help solving this problem.
The length of a rectangular sign is 3 feet longer than the width. If the
sign has space for 40 square feet of advertising, find its length and width.

Answer by pwac(253) About Me  (Show Source):
You can put this solution on YOUR website!
Let x=width
x+3=length
x(x+3)=40 expand and rearrange to get quadratic equation:
x%5E2%2B3x-40=0 which factors easily to
(x-5)(x+8)=0
x+8=0 givesx=-8
x-5=0 givesx=5
width= 5 feet
length=8 feet
Pete