Please help me with finding width of walkway around pool

adevine

New member
Joined
Mar 14, 2008
Messages
10


Hi folks,
I am having some trouble with this seemingly simple problem. I keep getting to:
4x^2+150x+934=0
But I can't find a way to factor that equation like I am used to doing. Any help would be appreciated. Thanks!
 

masters

Full Member
Joined
Mar 30, 2007
Messages
378
Re: Please help me with this problem

I'm not sure where you got your "934" in your equation.

The area of the pool with the sidewalk is (2x + 50)(2x + 25), which is 4x[sup:3obn90da]2[/sup:3obn90da] + 150x + 1250

Now, if you subract the area of the pool (25)(50) = 1250, you will have the area of the sidewalk which is 316 m[sup:3obn90da]2[/sup:3obn90da].

(4x[sup:3obn90da]2[/sup:3obn90da] + 150x + 1250) - 1250 = 316

Simplifying, 2x[sup:3obn90da]2[/sup:3obn90da] + 75x -158 = 0

This factors into (x - 2)(2x +79) = 0

x = 2 or x = -79/2

Since x cannot be negative (it's a length), then the sidewalk is 2 meters wide.
 

adevine

New member
Joined
Mar 14, 2008
Messages
10
Re: Please help me with this problem

Thanks very much. It's funny how a simple misunderstanding can ruin a whole problem.
 

TchrWill

Full Member
Joined
Jul 7, 2005
Messages
856
Re: Please help me with this problem

adevine said:


Hi folks,
I am having some trouble with this seemingly simple problem. I keep getting to:
4x^2+150x+934=0
But I can't find a way to factor that equation like I am used to doing. Any help would be appreciated. Thanks!

Alternatively:
2(50 + 2x) + 2(25)x = 316 or 2x^2 + 75x - 158 = 0 leading to the same answer as adevine came up with.
 
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