hello can someone please demonstrate how matrix is evaluated by expressing it in echelon form and use row reduction to solve it. it would be a great help.

k1+ L2+ Z = 20

3K -L+2Z = 22

2K+L-4Z=7

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- Apr 15th 2010, 10:35 PMsigma1matrix equation.
hello can someone please demonstrate how matrix is evaluated by expressing it in echelon form and use row reduction to solve it. it would be a great help.

k1+ L2+ Z = 20

3K -L+2Z = 22

2K+L-4Z=7 - Apr 16th 2010, 03:09 AMHallsofIvy
Actually, it is the other way around- row reduce in order to get the echelon form.

The "augmented matrix" for this system is $\displaystyle \begin{bmatrix} 1 & 2 & 1 & 20 \\ 3 & -1 & 2 & 22 \\ 2 & 1 & -4 & 7\end{bmatrix}$.

Now use row operations to put this into echelon form. For example, a first step would be to subtract three times the first row from the second row and subtract two times the first row from the third row:

$\displaystyle \begin{matrix}1 & 2 & 1 & 20 \\ 0 & -7 & -1 & -38 \\ 0 & -3 & -6 & -33\end{bmatrix}$

That take care of the first row. Now subtract 3/7 times the second row from the third row. - Apr 16th 2010, 08:09 AMsigma1
- Apr 16th 2010, 08:35 AMharish21
You might want to use this to find out where you are going wrong:

Linear Algebra Toolkit - Apr 16th 2010, 08:40 AMsigma1