Math Problem Help

[AgaBoogaBoo]

I feel like an idiot, but I can't figure out something very simple I am missing. Here is the problem:

A person wants to fence off a rectangular play-ground besides an apartment building. The building forms one boundary, so he needs to fence only the other three sides. The area of the playground is to be 11,250 sq m. He has enough material to build 325m of fence. Find the lenght and width of the playground.

Ansswer is 225x50 incase that helps...

 

[zer0burn]

your joking right youve already got the answer its easy

 

[Legendary]

X*Y=11,250
X+Y+Y = 325
via substitution
X*(2*(325-X)) = 11,250
solve for x, put back into 2nd equation

 

[LordMorpheus]

(2X)(325-2X)=11250
X= width (two sides are equal to X)
325-2X = length (opposite the appartment)

If you can't work that, then there is no hope for you.

 

[AgaBoogaBoo]

Originally posted by: Legendary
X*Y=11,250
X+Y+Y = 325
via substitution
X*(2*(325-X)) = 11,250
solve for x, put back into 2nd equation

Ok... thanks, I just realized I was using 350 the whole time instead of 325 after reading your response. Thanks! 🙂

 

[bleeb]

Originally posted by: Legendary
X*Y=11,250
X+Y+Y = 325
via substitution
X*(2*(325-X)) = 11,250
solve for x, put back into 2nd equation

That was like a HOT KNIFE through WARM BUTTER on a HOT DAY in the DESERT.

 

[zer0burn]

i hope that your not in highschool yet or god damn there teaching you some easy $hit

 

[RossGr]

Let x and y be the sides.

We know that

2x+y=325

and

xy=11250

so
y=325-2x

x(325-2x)=11250

x^2 - (325/2) - (11250/2) = 0

Find the roots of the above quadradic.

 

[phatj]

_____.__X___
| | |
| | |
| | | Y
| | |
| | |
|____|._____ |

X

A = XY
11250 = XY

Materials: 325m = 2*X + y
so........... (325 - 2X) = y

Plug that in to the Area formula

11250 = X * (325 - 2X)
11250 = 325*X - 2X^2
X = 50 or X = (225/2)
Well since you know the area is 50, X = 50

11250 = 50 * Y
11250/50 = Y
Y = 225

 

[phatj]

edit: Double post and horrible illustration

 

[AgaBoogaBoo]

Originally posted by: zer0burn
i hope that your not in highschool yet or god damn there teaching you some easy $hit

Alright! Listen! I frickin wrote 350 instead of 325 and kept trying to make it work... And Yes! I AM IN HS! I'm taking Honors Algebra 2, mind you, its pretty challenging. Sure, this isn't the hardest problem, but if you look at others they can take some time and thinking... don't you ever just make a small mistake and can't figure it out?