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## #1 2012-12-03 11:18:15

BarandaMan
Guest

### Urgent Help solving Linear Equation.......

Need to solve:

Maximise (8/3)P1 + 8P2 + 8P3 + 10P4 subject to........

1. (4/3)P1+6P2>(or equal to, for all) 2P1 + 5P2 .... SO P1 < (3/2) P2.
2. 2P3 + 5P4 > (4/3)P3 + 6P4.....so P4 < (2/3)P3
3. (4/3)P1 + 6P3 > 2P1 + 5P3....SO P1<(3/2)P3
3. 2P2 + 5P4 > (4/3) P2 + 6P4.....SO P4 < (2/3) P2

PLEASE help me solve this. How do I do it? What do you get? Help help help!

## #2 2012-12-03 12:28:33

bobbym
From: Bumpkinland
Registered: 2009-04-12
Posts: 106,389

### Re: Urgent Help solving Linear Equation.......

Hi BarandaMan;

Looks like a linear programming problem. Have you studied them yet?

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
No great discovery was ever made without a bold guess.

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## #3 2012-12-03 12:46:23

BarandaMan
Guest

### Re: Urgent Help solving Linear Equation.......

Unfortunately not, but it seems from my experience we are not meant to have...it is a very small part of the question (At the end)but obviously it is a big new thing to learn.

How can I solve this? Thanks bobbym

## #4 2012-12-03 12:57:18

bobbym
From: Bumpkinland
Registered: 2009-04-12
Posts: 106,389

### Re: Urgent Help solving Linear Equation.......

Hi;

Is this the problem?

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
No great discovery was ever made without a bold guess.

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## #5 2012-12-03 13:11:23

BarandaMan
Guest

### Re: Urgent Help solving Linear Equation.......

Yes:P this is correct

## #6 2012-12-03 13:15:36

bobbym
From: Bumpkinland
Registered: 2009-04-12
Posts: 106,389

### Re: Urgent Help solving Linear Equation.......

Hi;

Without even talking about a possible method of solution I am having a problem right there. I am getting no maximum with those constraints. Have you copied the problem exactly?

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
No great discovery was ever made without a bold guess.

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## #7 2012-12-03 13:30:00

BarandaMan
Guest

### Re: Urgent Help solving Linear Equation.......

I forgot to add that, 0 is less than or equal to each P which is less than or equal to 1. and P1+P2+P3+P4=1. Does this help? :d

## #8 2012-12-03 13:34:24

bobbym
From: Bumpkinland
Registered: 2009-04-12
Posts: 106,389

### Re: Urgent Help solving Linear Equation.......

Hi;

Are those the last of the constraints?

With those I can get a maximum of

when

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
No great discovery was ever made without a bold guess.

Offline

## #9 2012-12-03 13:59:53

BarandaMan
Guest

### Re: Urgent Help solving Linear Equation.......

YAY!!!

Ok, I got the same answer, but basically by using the 'fixed formula' for the type of question we had which we were told in class.

I just want to know HOW i would solve this using the inequalities so that I know I can really do this without memorizing a formula...if that makes sense. Please can you show me how to solve this?

## #10 2012-12-03 14:09:52

bobbym
From: Bumpkinland
Registered: 2009-04-12
Posts: 106,389

### Re: Urgent Help solving Linear Equation.......

I did it by computer. It was too complicated to be done by hand. If you have a fixed formula, please post it.

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
No great discovery was ever made without a bold guess.

Offline