#1**+18 **

I didn't know how to do this so I gave myself a quick lesson from here

Watch th video and work through the video example

then put it together with your knowledge of how elimination method to solve simultaneous equations works.

$$\begin{pmatrix}

2 &1&0&|-4 \\

0 &-2&4&|+0 \\

3 &0&-2&|-11 \\

\end{pmatrix}$$

First you need to get rid of the 3 in the bottom left corner.

1) multiply R1 by3 **and** R3 by 2 WRITE down the new matrix

2) R1-R3 replaces R3 WRITE down the new matrix (the 3 has been replaced with a 0)

NOW there is a 3 in R3, C2 You have to get rid of it

3) mult R2 by 3 and mult R3 by 2 WRITE down the new matrix

4) R2+R3 replaces R3 WRITE down the new matrix (the 6 has been replaced with a 0)

NOW the diagonal must only contain ones

5) Multiply R1 by 1/6, Multiply R2 by -1/6 and multiply R3 by 20

And you should be able to take it from there

answer

x=-3, y=2, and z=1

Melody
Mar 24, 2015

#1**+18 **

Best Answer

I didn't know how to do this so I gave myself a quick lesson from here

Watch th video and work through the video example

then put it together with your knowledge of how elimination method to solve simultaneous equations works.

$$\begin{pmatrix}

2 &1&0&|-4 \\

0 &-2&4&|+0 \\

3 &0&-2&|-11 \\

\end{pmatrix}$$

First you need to get rid of the 3 in the bottom left corner.

1) multiply R1 by3 **and** R3 by 2 WRITE down the new matrix

2) R1-R3 replaces R3 WRITE down the new matrix (the 3 has been replaced with a 0)

NOW there is a 3 in R3, C2 You have to get rid of it

3) mult R2 by 3 and mult R3 by 2 WRITE down the new matrix

4) R2+R3 replaces R3 WRITE down the new matrix (the 6 has been replaced with a 0)

NOW the diagonal must only contain ones

5) Multiply R1 by 1/6, Multiply R2 by -1/6 and multiply R3 by 20

And you should be able to take it from there

answer

x=-3, y=2, and z=1

Melody
Mar 24, 2015