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put this solution on YOUR website! If the length of a rectangular field is 8 feet more than double of its width. Find the dimensions of the field if its area is 540 square feet?
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Let x = width
then from "length of a rectangular field is 8 feet more than double of its width"
2x+8 = length
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x(2x+8) = 540
2x^2+8x = 540
x^2+4x = 270
x^2+4x-270= 0
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Since you can't factor you must use the quadratic equation.
This will result in:
x = {14.55, -18.55}
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Since width can't be negative:
x = 14.55 feet
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Length:
2x+8 = 2(14.55)+8 = 37.1 feet
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Dimensions: 14.55 by 37.1 feet
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Details of quadratic:
| Solved by pluggable solver: SOLVE quadratic equation with variable |
Quadratic equation  (in our case  ) has the following solutons:
For these solutions to exist, the discriminant  should not be a negative number.
First, we need to compute the discriminant :  .
Discriminant d=1096 is greater than zero. That means that there are two solutions:  .
Quadratic expression  can be factored:
Again, the answer is: 14.5529453572468, -18.5529453572468.
Here's your graph:
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