SOLUTION: a rectangular parking lot has length that is 9 yards less than twice its width. if the area of the land is 221 square yards, what are the demensions of the land?

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Question 898805: a rectangular parking lot has length that is 9 yards less than twice its width. if the area of the land is 221 square yards, what are the demensions of the land?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
(2w-9)w = 221
2w^2 - 9w - 221 = 0
w = 10.3470673703508
find length = 2w-9
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 2x%5E2%2B-9x%2B-121+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%28-9%29%5E2-4%2A2%2A-121=1049.

Discriminant d=1049 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28--9%2B-sqrt%28+1049+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%28-9%29%2Bsqrt%28+1049+%29%29%2F2%5C2+=+10.3470673703508
x%5B2%5D+=+%28-%28-9%29-sqrt%28+1049+%29%29%2F2%5C2+=+-5.84706737035082

Quadratic expression 2x%5E2%2B-9x%2B-121 can be factored:
2x%5E2%2B-9x%2B-121+=+2%28x-10.3470673703508%29%2A%28x--5.84706737035082%29
Again, the answer is: 10.3470673703508, -5.84706737035082. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+2%2Ax%5E2%2B-9%2Ax%2B-121+%29