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#1 2005-05-26 22:37:22

maths_buff
Member
Registered: 2005-05-26
Posts: 14

Plotting Linear Equations with Three Variables

How would I plot linear equations with three variables?

Here's my own problem:

x + y + z = 6
2x - 3y + 4z = 4
x + 2y - z = 6

In this problem I made, x = 3, y = 2 and z = 1

I have tried downloading some programs but they keep saying my syntax is wrong.

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#2 2005-05-26 23:41:45

Milos
Member
Registered: 2005-05-06
Posts: 44

Re: Plotting Linear Equations with Three Variables

You have a system of 3 equations here:
From the first one find x, it is
x=6-y-z
put it in the second one:
2(6-y-z)-3y+4z=4
12-2y-2z-3y+4z=4
-5y=-8-2z   /*(-1)
5y=8+2z
y=(8+2z)/5
Now put x, y in the third one:
6-(8+2z)/5-z+(16+4z)/5-z=6
6+(8+2z)/5-2z=6 
(8+2z)/5=2z         /*5
8z=8
z=1
than:y=(8+2)/5=2
and:x=6-2-1=3
There are some other ways to do it- shorter ones :). If you are interested, I can show you.

Last edited by Milos (2005-05-26 23:42:11)

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#3 2005-05-26 23:44:25

maths_buff
Member
Registered: 2005-05-26
Posts: 14

Re: Plotting Linear Equations with Three Variables

I think you may have misunderstood me, Milos. I know what x, y and z; I'm looking on how to plot/graph them.

Notice how I said x = 3, y = 2 and z = 1 in my first post?

Cheers,

Kris

Last edited by maths_buff (2005-05-26 23:45:56)

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#4 2005-05-27 05:57:24

Milos
Member
Registered: 2005-05-06
Posts: 44

Re: Plotting Linear Equations with Three Variables

ups smile. My apologies

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