9514 1404 393
Answer:
Explanation:
Let w represent the width. Then the length is w+9, and the sum of length and width is ...
 w +(w+9) = 15
 2w = 6 . . . . . . . subtract 9
 w = 3 . . . . . . . . divide by 2
 w+9 = 12 . . . . . find the length
The width should be 3 feet; the length should be 12 feet.