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put this solution on YOUR website! a garden in the form of a square is surrounded by a walkway 2m wide. What are the dimensions of the garden if the area of the walkway is 800 square metres?
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Let x = length of one side of garden
then
(x+4)(x+4)= 800
x^2+8x+16= 800
x^2+8x-784= 0
applying the "quadratic formula" we get:
x = {24.28, -32.28}
throw out the negative solution (extraneous) leaving:
x = 24.28 m
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details of quadratic follows:
| 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=3200 is greater than zero. That means that there are two solutions:  .
Quadratic expression  can be factored:
Again, the answer is: 24.2842712474619, -32.2842712474619.
Here's your graph:
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