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•  » How do you solve three equations in three unknowns?

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BarandaMan
2012-11-29 07:25:13

#### bobbym wrote:

Unfortunately at one time I loved physics and group theory. I actually thought I was doing mathematics... Then like Saul, I was struck by lightning and saw the light. Computational mathematics!

Hahahaha! That is brilliant!

bobbym
2012-11-29 07:12:36

Unfortunately at one time I loved physics and group theory. I actually thought I was doing mathematics... Then like Saul, I was struck by lightning and saw the light. Computational mathematics!

BarandaMan
2012-11-29 07:03:51

I am doing a bit of EVERYTHING!
What did you specialise in??

bobbym
2012-11-29 06:36:02

Your work looks like you are doing some kind of physics. You have my sympathy...

BarandaMan
2012-11-29 05:42:37

DONE IT!!!

Basically, I missed out a '2p2' a LOT earlier on, I went through it all over and wrote it again and I was like, where did that 2p2 dissappear?! (I forgot it off one line of algebra)...went through everything and the end three equations were very simple thanks to your guidance. Thank you again. LOVE it when it works!

bobbym
2012-11-28 14:20:19

Hi;

Maths is SO stressful sometimes and i try SO hard,

Math is hard work for everybody. Go over how you set the problem up there is certainly a mistake there.

BarandaMan
2012-11-28 14:16:00

THANK you for guiding me on this. Please don't waste your time here, I will go over this freshly again and see what I have done wrong. I HAVE to get to a stage with three equations in three unknowns, it just means my numbers were wrong earlier because a negative price cannot happen in this particular question, but thanks to you at least i can solve three equations in three unknowns!

Maths is SO stressful sometimes and i try SO hard, i am really good at mental maths but as you can see I am poor at most else, it really drags because i want to do well. thank you again for your help bobby.

bobbym
2012-11-28 14:11:06

P1 = ( - 1 / 2 ). If that does not fit then you have set the problem up wrong.

BarandaMan
2012-11-28 14:09:34

Wait I think I just did it, i got p1 = -1/2. We cannot have a negative price so I won't solve for p2 and p3 yet, I must have done something wrong earlier. This is awful I will not be asleep for a while.

bobbym
2012-11-28 14:08:23

Hi;

From the first equation you get

You substitute for P1 in equation 3. That gives 2 equations with 2 unknowns. Can you solve now?

BarandaMan
2012-11-28 13:58:12

#### bobbym wrote:

Did you use equation 1 and substitute for P1 into equation  3?

I tried substituting everything into everything, I keep going round in circles and have two unknowns in every equation. But this can be done apparantly it shouldn't be too difficult. I just cannot see it.

bobbym
2012-11-28 09:03:10

Did you use equation 1 and substitute for P1 into equation  3?

BarandaMan
2012-11-28 08:44:00

#### bobbym wrote:

Hi;

Do you know how to use substitution?

I think so, that's what I tried but I always got it wrong!

bobbym
2012-11-28 08:43:04

Hi;

Do you know how to use substitution?

BarandaMan
2012-11-28 08:40:44

Oh my god?! How did you do that? This is incredible. Apologies for the delayed response, internet went down for over an hour.