Posted by whizkidd
3x + 2y - z = 0 4x + 9y + 2z = 0 5x - 2z = 2 . How do i solve these three equations simultaneously to find x, y and z? I know this is very simple but i am simply not getting it. Thx! ;-)
Posted by plasmadog
Posted by whizkidd
Er....... Thanks! :-D
Posted by SnowBear
com'n think
Posted by plasmadog
sorry...
i posted on wap, and there might have been some problem
x=.9629
y= -0.7407
z=1.4074
Posted by whizkidd
Pleaseee do not torture me! I have spent half a day pondering over it. Please help me!
Posted by Grimslade
Yes, but how's it done? I just (I confess!) spent a half-hour factoring, adding and subtracting, but I got nowhere? Anyone willing to give a quick refresher?
Posted by methylated_spirit
do your own homework! You will never learn if someone just tells you!
_________________
Hello, Scroto!
950 green bottles hanging on the wall...
[ This Message was edited by: masseur on 2004-10-21 13:56 ]
Posted by Johnex
:-) do you have a ti? If so, download the polyroot finder and simultaneous equation solver. It does the trick.
Posted by whizkidd
Please someone explain how it is solved. I have the answers but how to get it is what is troubling me. The answers are x=2, y=-1 and z=4.
Posted by masseur
I don't think he wants the answers, I think he wants to know how to do it.
Its been a long time since I did simultaneous equations but... I'll try to start you off..
3x + 2y - z = 0
so by taking Z to the other side of the equal sign you get
z = 3x + 2y
now you have z expressed in terms of x and y can substitude for y in the 3rd equation
5x - 2(3x + 2y) = 2
which simplifies to
5x - 6x - 4y = 2
or simplified further
-x - 4y = 2
now swap 2 and x to give
-2 - 4y = x
so we can now substitute for x and z into the second equation to determine the value of y
once you have the numerical value of y you can supply that into the first equation (substituting z in terms of x too) and you can derive the numerical value of x leaving a simple task to find the value of Z
Posted by Aled
Just buy a calculator that does simultaneous equations.
Posted by masseur
can you use those in exams these days?
don't you still have to know how to do it by hand?
Posted by whizkidd
CAN ANYONE HELP ME? Instead of wasting Esato's bandwidth? Please. I am getting restless. :-(
Posted by masseur
@whizzkid, read back a few posts, I have already helped you!!
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[ This Message was edited by: masseur on 2004-10-21 14:19 ]
Posted by Krubach
He's expecting that someone does it for him...
It's not that dificult whizzkid! Just follow masseur's explanation.
Posted by Johnex
Masseur did it right.
Posted by krypton65
Use a casio fx991 ms, its easy with that.
Posted by plasmadog
You can also use the determinants to solve the problem. Any higher math textbooks will tell you. Else if you want fast answers, substitute some values by trial and error.
Posted by Krubach
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No way it would be fast...
Posted by whizkidd
Thx Masseur! I was trying to connect all these time. I may have some similar doubts in the future. Hope you'd be there to clear my mathematic problems! Thx again! You can lock this now. mwah!! :-D
Posted by plasmadog
it would be faster if it were a multiple choice question
but... u can substitute the answers in any of the equations to check if its correct.
Posted by kimcheeboi
wow math questions galore in the mobile phone free zone!
Posted by Ayush
Its a pity I'm no good at math.
(Im learning functions and limits at the momoent 
)
Posted by maddav
Shame i missed it earlier, I had a free period before Maths!