Word Problem: A parking lot measures 100 by 130 feet.

pochoa

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Feb 2, 2006
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I can not figure out what formula I should be using for this! Heres the problem:

A parking lot measures 100 by 130 feet. A sidewalk of uniform width is to completely surround the lot. If the sidewalk covers 1659 sq ft. how wide can the sidewalk be?

Can anyone help me get started? Thanks!
 

stapel

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pochoa said:
I can not figure out what formula I should be using for this!
There is no one "master formula" that will solve every word problem. You generally need to create the formula for each problem.

pochoa said:
A parking lot measures 100 by 130 feet. A sidewalk of uniform width is to completely surround the lot. If the sidewalk covers 1659 sq ft. how wide can the sidewalk be?
Have you made a drawing yet?

Eliz.
 

pochoa

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Yes I have. This is what I have so far:

(100+2x)(130+2x)=1659

4x^2+460-1659=0

Does this seem right so far? If so, where do I go from here? Factor? Quad . eq?

Thanks for your help![/img]
 

stapel

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pochoa said:
This is what I have so far: (100+2x)(130+2x)=1659
Isn't the "1659" the area of the walk alone? That is, doesn't that measure exclude the inner 13000 ft<sup>2</sup> parking lot?

And since the parking lot is bigger than 1659, then 1659 cannot be the sum of the lot's and the walk's area, can it...?

Eliz.
 

Denis

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pochoa said:
(100+2x)(130+2x)=1659
4x^2+460-1659=0
HOW in heck do you get 4x^2 + 460 as the result of (100+2x)(130+2x) :?:
That should be 4x^2 + 460x + 13000;
guess it don't matter too much: equation is not correct (as Stapel told you).
 

pochoa

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ok, i redid the problem . I got 3.5 ft for the answer. Am I still way off? thanks!
 

Denis

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That's correct; 4x^2 + 460x - 1659 = 0 ; x = 3.5
 
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