# matrices

• Sep 24th 2007, 09:09 PM
jay123
matrices
hello. my question is this:

2x-y+3=1
-x-3y+2z=-4
-3x+y+7z=-2
• Sep 24th 2007, 09:13 PM
Jhevon
Quote:

Originally Posted by jay123
hello. my question is this:

2x-y+3=1
-x-3y+2z=-4
-3x+y+7z=-2

saying "matrices" is not specific enough. there are many ways you can use matrices to solve this. what methods have you learned so far? what method are you required to use here?
• Sep 24th 2007, 09:16 PM
jay123
Row of operation to an Augmented Matrix
• Sep 24th 2007, 09:47 PM
jay123
is there any way you can help me.
I know there is a system to solving these equations. such as add the 1st two roles to get the 1st row but i cant remember the rest.
• Sep 25th 2007, 03:46 AM
WWTL@WHL
Are you talking about echelon form?

The most common way (I think) of doing this is finding the inverse of the matrix. Have you learned how to do that?
• Sep 25th 2007, 07:39 AM
Jhevon
Quote:

Originally Posted by WWTL@WHL
Are you talking about echelon form?

yes, that's what he's talking about. i will go all the way to reduced row echelon, i like doing that.

Quote:

Originally Posted by jay123
Row of operation to an Augmented Matrix

ok, here goes. i will not type what i did to get from one step to another, so if you don't understand something, just ask.

The augmented matrix is:

...$\displaystyle x$.....$\displaystyle y$....$\displaystyle z$
$\displaystyle \left| \begin {array}{ccc|c} 2 & {-1} & 3& 1 \\ {-1}&{-3} & 2& {-4} \\ {-3}&1 &7 &{-2} \end {array} \right|$

$\displaystyle \left| \begin {array}{ccc|c} 1& 3& {-2}& 4\\ 0& -7& 7&-7 \\ 0& 10&1 &10 \end {array} \right|$

$\displaystyle \left| \begin {array}{ccc|c} 1& 3& -2&4 \\ 0& 1& -1&1 \\ 0& 10& 1&10 \end {array} \right|$

$\displaystyle \left| \begin {array}{ccc|c} 1& 0& 1&1 \\ 0& 1& -1&1 \\ 0& 0& 11& 0\end {array} \right|$

$\displaystyle \left| \begin {array}{ccc|c} 1& 0& 1&1 \\ 0&1 &0 &1 \\ 0& 0& 1& 0\end {array} \right|$

$\displaystyle \left| \begin {array}{ccc|c} 1& 0& 0&1 \\ 0& 1&0 &1 \\ 0& 0& 1& 0\end {array} \right|$