A soccer field is bordered on three sides by a parking lot of width x. The total length of the field and parking lot is 300 m, and the total width is 200 m. The area of the field is 30,000 m2. How wide is the parking lot

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Answer:

Step-by-step explanation:

Assuming the parking lot is along both widths of the field and only once along the length:

 

the length is (300 - 2x)

the width is (200 -x)

the area is (300-2x)(200-x) = 30000

         60000 -300x - 400x +2x^2 = 30000

        2x^2 -700x + 30000 = 0

         x^2 - 350x + 15000 = 0

          (x    -   300    )(x   -    50    ) = 0

             x = 300 or x=50

x=300 results in negative measures.

the parking lot is x=50 wide

the length of the field is 200, the width of the field is 150

By solving a system of equations, we will see that are two possible solutions for the width:

x = 75m

x = 100m

How wide is the parking lot?

Remember that for a rectangle of length L and width W, the area is:

A = L*W

Here we know the length of the field and the parking lot, that we can write as:

L' = L + 2x  = 300m

x is the width of the parking lot.

The width is:

W' = W + x = 200m

(here x appears only once because we know that the parking lot only surrounds 3 sides of the field).

And the area of the field is 30,000m^2, then:

W*L = 30,000m^2

So we have 3 equations:

L + 2x  = 300m

W + x = 200m

W*L = 30,000m^2

This is a system of equations.

Using the third one, we can isolate W to get:

W = (30,000m^2)/L

Now we can replace this on the second equation to get:

(30,000m^2)/L + x = 200m

Now we need to isolate L (because we want a solution for x), so we get:

30,000m^2 = (200m - x)*L

(30,000m^2)/(200m - x) = L

Now we can replace this on the last equation to get:

L + 2x  = 300m

(30,000m^2)/(200m - x) + 2x = 300m

Now we can solve this for x.

30,000m^2 + 2x*(200m - x) = 300m*(200m - x)

- 4x^2 + 700m*x -30,000m^2 = 0

So we have a quadratic equation, the solutions are given by Bhaskara's formula:

[tex]x = \frac{-700m \pm \sqrt{(700m)^2 - 4*(-4)*-30,000m^2} }{2*-4} \\\\x = \frac{-700m \pm 100m }{-8}[/tex]

So there are two possible solutions:

x = (-700m + 100m)/-8 = 75m

x = (-700m - 100m)/-8 = 100m

Which will depend on the values we take for L and W.

If you want to learn more about systems of equations, you can read:

https://brainly.com/question/13729904