Gmat Prep Question Please help - Area of a square garden

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by DanaJ » Sat Jan 17, 2009 11:00 am
Let's say that x is the length of one side of the garden.
A = x^2
P = 4x
Then you have: A = 2P + 9, which means that x^2 = 8x+9. That is the equivalent of x^2 - 8x - 9 = 0. That in turn is the equivalent of (x - 9)(x +1) = 0. That gives us x = 9 or x = -1. Since x is the length of a side, it can only be positive. So x = 9. P will be 4*9 = 36.

Answer: B.

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by dubeystuts » Sat Jan 17, 2009 11:46 am
Thank You very much.

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by deepoe » Tue May 05, 2009 12:07 am
I don't understand the 8x :$

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by DanaJ » Tue May 05, 2009 1:03 am
A = 2P + 9

P = 4x or four times the length of one side, meaning that 2P + 9 = 2*4x + 9 = 8X + 9

A = x^2 - area of square

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by deepoe » Tue May 05, 2009 1:57 am
Ooohhh ok ok! you already did 4 times in the equation :$ nThanks!