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put this solution on YOUR website!A flat panel monitor are such that its length is 3 in. more than its width. If length were doubled and if the width were decreased by 1 in., the area would be increased by 150 in.2(squared). What are the length and width of flat panel monitor?
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Let w = width of monitor
then
w+3 = length of monitor
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double length = 2(w+3)
width decreased by 1 = w-1
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2(w+3)(w-1) =150
2(w^2-w+3w-3) =150
2(w^2+2w-3) =150
w^2+2w-3 =75
w^2+2w-78 = 0
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Using the quadratic equation to solve, we find the roots as:
w = {7.888, -9.888}
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We can toss out the negative solution since it doesn't make sense.
w = 7.888 inches (width)
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length:
w+3 = 7.888+3 = 10.888 inches (length)
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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=316 is greater than zero. That means that there are two solutions:  .
Quadratic expression  can be factored:
Again, the answer is: 7.88819441731559, -9.88819441731559.
Here's your graph:
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