SOLUTION: Suppose that the length of a rectangle is 3 inches longer than the width and that the perimeter of the rectangle is 78.Set up an equation involving only L, the length of the rectan

Algebra ->  Rectangles -> SOLUTION: Suppose that the length of a rectangle is 3 inches longer than the width and that the perimeter of the rectangle is 78.Set up an equation involving only L, the length of the rectan      Log On


   

Question 109136: Suppose that the length of a rectangle is 3 inches longer than the width and that the perimeter of the rectangle is 78.Set up an equation involving only L, the length of the rectangle.Solve this equation algebraically to find the length of the rectangle. Find the width as a slope

Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!
if the length+of a rectangle is 3 inches+longer than the width, then we have
L+=+W+%2B+3in.....=> W=+L+-+3
if the perimeter+=+P of the rectangle is 78, then we have:
P+=+2%28L%2BW%29
78+=+2+%28+L+%2B+%28L+-+3%29%29
78+=+2%282L+-+3%29
78+=+4L+-+6
4L+=+78+%2B+6
4L+=+84,,,,,,,divide both sides by 4
L+=+21
then:
W+=+21+-+3
W+=+18
check:
2%2821+%2B+18%29+=+2%2A+39+=+78