Esato

Forum > General discussions > Non mobile discussion > How do i solve this simple algebraic problem?

12  Next
Author How do i solve this simple algebraic problem?
whizkidd
W950 Blue
Joined: May 14, 2004
Posts: > 500
From: India
PM, WWW
Posted: 2004-10-21 13:59
Reply with quoteEdit/Delete This PostPrint this post
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! ;-)

This message was posted from a T230

plasmadog
K750
Joined: May 06, 2004
Posts: > 500
From: Beantown, India
PM
Posted: 2004-10-21 14:20
Reply with quoteEdit/Delete This PostPrint this post

This message was posted from a T630

whizkidd
W950 Blue
Joined: May 14, 2004
Posts: > 500
From: India
PM, WWW
Posted: 2004-10-21 14:24
Reply with quoteEdit/Delete This PostPrint this post
Er....... Thanks! :-D

This message was posted from a T230

SnowBear
K700
Joined: Oct 10, 2003
Posts: > 500
From: Sweden
PM, WWW
Posted: 2004-10-21 14:31
Reply with quoteEdit/Delete This PostPrint this post
com'n think [addsig]
plasmadog
K750
Joined: May 06, 2004
Posts: > 500
From: Beantown, India
PM
Posted: 2004-10-21 14:35
Reply with quoteEdit/Delete This PostPrint this post
sorry...
i posted on wap, and there might have been some problem

x=.9629
y= -0.7407
z=1.4074
whizkidd
W950 Blue
Joined: May 14, 2004
Posts: > 500
From: India
PM, WWW
Posted: 2004-10-21 14:37
Reply with quoteEdit/Delete This PostPrint this post
Pleaseee do not torture me! I have spent half a day pondering over it. Please help me!

This message was posted from a T230

Grimslade
W995 Red
Joined: Jul 25, 2004
Posts: 464
From: London
PM
Posted: 2004-10-21 14:53
Reply with quoteEdit/Delete This PostPrint this post
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?
methylated_spirit
P900 no flip
Joined: Jul 07, 2004
Posts: > 500
From: Bonnie Scotland
PM
Posted: 2004-10-21 14:53
Reply with quoteEdit/Delete This PostPrint this post
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 ]
Johnex
P990
Joined: Nov 26, 2002
Posts: > 500
From: Stockholm/Sweden
PM, WWW
Posted: 2004-10-21 14:55
Reply with quoteEdit/Delete This PostPrint this post
:-) do you have a ti? If so, download the polyroot finder and simultaneous equation solver. It does the trick.

This message was posted from a Z1010

whizkidd
W950 Blue
Joined: May 14, 2004
Posts: > 500
From: India
PM, WWW
Posted: 2004-10-21 15:02
Reply with quoteEdit/Delete This PostPrint this post
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.

This message was posted from a T230

masseur
P910
Joined: Jan 03, 2003
Posts: > 500
From: Sydney, London
PM
Posted: 2004-10-21 15:04
Reply with quoteEdit/Delete This PostPrint this post
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
Aled
P910
Joined: Nov 25, 2002
Posts: 320
From: Wales
PM
Posted: 2004-10-21 15:08
Reply with quoteEdit/Delete This PostPrint this post
Just buy a calculator that does simultaneous equations.

This message was posted from a T610

masseur
P910
Joined: Jan 03, 2003
Posts: > 500
From: Sydney, London
PM
Posted: 2004-10-21 15:09
Reply with quoteEdit/Delete This PostPrint this post
can you use those in exams these days?
don't you still have to know how to do it by hand?
whizkidd
W950 Blue
Joined: May 14, 2004
Posts: > 500
From: India
PM, WWW
Posted: 2004-10-21 15:11
Reply with quoteEdit/Delete This PostPrint this post
CAN ANYONE HELP ME? Instead of wasting Esato's bandwidth? Please. I am getting restless. :-(

This message was posted from a T230

masseur
P910
Joined: Jan 03, 2003
Posts: > 500
From: Sydney, London
PM
Posted: 2004-10-21 15:13
Reply with quoteEdit/Delete This PostPrint this post
@whizzkid, read back a few posts, I have already helped you!!

_________________
...Unless I'm very much mistaken
my K700 review

[ This Message was edited by: masseur on 2004-10-21 14:19 ]
Access the forum with a mobile phone via esato.mobi