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bobbym
2010-06-20 03:22:19

We have the 2 equations:

P = 100 = 2L + 2W

A = 25 = L * W     These are easy. But not easy to solve for all those variables. So we try to eliminate one. We solve for the L from the first equation.

L = 100 - 2W = 50 - W

25 = L * W   Substitute 50 - W for L

25 = ( 50 - W ) W  This is a quadratic, so expand it.

25 = 50W - W^2

W^2 - 50 W + 25 = 0

Now solve by the quadratic formula. Are you Okay with this? Or do you need more help? After you get the answer I will go over the equations with you.

2010-06-20 01:58:52

Please can you explain that actually what this question is asking.  What this equation will do. I still don't know how to come up the equation. Am I finding length which is equal to this function. It is quadratic equation, so there are two W??
I am not good in math. Sorry.

bobbym
2010-06-19 09:20:05

Hi;

Start by using the equations for A and P.

P = 100 = 2L + 2W

A = 25 = L * W

Solving from the first equation:

L = 100 - 2W = 50 - W

Can you finish from here?

2010-06-19 09:02:05

A rectangle or square with perimeter 100cm, area 25 cm² what will be the equation.
is it
w²+25w+100
w²+50w+25
w²+25w-100
the third option i dont remember.