SOLUTION: The length of a rectangle is 7 m more than twice the width, and the area of the rectangle is 99 m2 . Find the dimensions of the rectangle.

Algebra ->  Surface-area -> SOLUTION: The length of a rectangle is 7 m more than twice the width, and the area of the rectangle is 99 m2 . Find the dimensions of the rectangle.       Log On


   



Question 1116613: The length of a rectangle is
7 m
more than twice the width, and the area of the rectangle is
99 m2
. Find the dimensions of the rectangle.

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +w+ = the width in meters
+L+=+2w+%2B+7+ = the length in meters
---------------------------------
+A+=+w%2AL+
+A+=+w%2A%28+2w+%2B+7+%29+
+99+=+w%2A%28+2w+%2B+7+%29+
+99+=+2w%5E2+%2B+7w+
+2w%5E2+%2B+7w+-+99+=+0+
+%28+2w+-+11+%29%2A%28+w+%2B+9+%29+=+0+
( you can use quadratic formula to solve.
I just took a guess )
+2w+=+11+
+w+=+11%2F2+
and
+L+=+2w+%2B+7+
+L+=+2%2A%28+11%2F2+%29+%2B+7+
+L+=+18+
---------------------------
The dimensions are 5.5 x 18
-------------------------------
check answer:
+A+=+w%2A%28+2w+%2B+7+%29+
+A+=+%2811%2F2%29%2A%28+2%2A%2811%2F2%29+%2B+7+%29+
+A+=+%28+11%2F2+%29%2A11+%2B+77%2F2+
+A+=+121%2F2+%2B+77%2F2+
+A+=+198%2F2+
+A+=+99+ m2
OK