A garden measuring 8 feet by 12 feet will have a walkway around it. The walkway has
a uniform width, and the area covered by the garden and walkway is 192 square feet.
What is the width of the walkway?
O 3.5 feet
O 6 feet
O 2 feet
O 4 feet

Respuesta :

Answer:

2 feet

Step-by-step explanation:

By solving a quadratic equation, we will see that the width of the walkway must be 2 ft.

How to get the width of the walkway?

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

A = L*W

In this case, we know that the dimensions are:

  • Length = 8ft
  • Width = 12ft

Now, if we add a walkway of width x all around the garden, the new dimensions of the garden are:

  • Length = 8ft + 2x
  • Width = 12ft + 2x

Now with these dimensions, the area is 192 ft^2, then we can write:

192 ft^2  = (8ft + 2x)*(12ft + 2x)

Now we need to solve that for x:

192 ft^2 = 96ft^2 + 4x^2 + 40ft*x

0 = 96ft^2 - 192ft^2 + 4x^2 + 40ft*x

0 = 4x^2 + 40ft*x - 96ft^2

This is a quadratic equation, the solutions are given by Bhaskara's formula:

[tex]x = \frac{-(40ft) \pm \sqrt{(40ft)^2 - 4*4*(-96ft^2)} }{2*4} \\\\x = \frac{-(40ft) \pm 56ft }{8}[/tex]

Notice that we have two solutions, but we only care for the positive one, so we take:

x = (-40ft + 56ft)/8 = 2ft

So the width of the walkway must be 2ft.

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

https://brainly.com/question/1214333

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