SOLUTION: The length of a rectangle is 5 times its width. The area is 86 square meters. Find the length of the rectangle. (Show your solution using Quadratic Equation)

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons -> SOLUTION: The length of a rectangle is 5 times its width. The area is 86 square meters. Find the length of the rectangle. (Show your solution using Quadratic Equation)      Log On


   

Question 353842: The length of a rectangle is 5 times its width. The area is 86 square meters. Find the length of the rectangle. (Show your solution using Quadratic Equation)
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
Hi,
Let x represent the width. Then 5x would be the length.
Area of rectangle = l*w
.
question states:
5x%2Ax+=+86m%5E2
.
x%5E2+=+%2886%2F5%29m%5E2
.
x%5E2+-+%2886%2F5%29m%5E2+=+0
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
.
x+=+%280+%2B-+sqrt%28+0%5E2-4%2A1%2A%28-86%2F5%29+%29%29%2F%282%2A1%29+
.
x+=+%280+%2B-+sqrt%2868.8+%29%29%2F%282%29+
x is +-4.148