SOLUTION: The perimeter of a rectangle is 42m.The length is 9m more than twice the width. Find the dimensions.

Algebra ->  Rectangles -> SOLUTION: The perimeter of a rectangle is 42m.The length is 9m more than twice the width. Find the dimensions.      Log On


   

Question 305554: The perimeter of a rectangle is 42m.The length is 9m more than twice the width. Find the dimensions.
Answer by graphmatics(170) About Me  (Show Source):
You can put this solution on YOUR website!
If w is the width of the rectangle and l is the length then:
perimeter+=+2%2Aw%2B2%2Al+ but
l+=+2%2Aw%2B9+ and
perimeter+=+42+ so:
42+=+2%2Aw%2B2%2A%282%2Aw%2B9%29+
42+=+2%2Aw%2B4%2Aw%2B18+
42-18+=+6%2Aw+
24+=+6%2Aw+
24%2F6+=+w+
4+=+w+
so:
l+=+2%2A4%2B9+
l+=+17+