Hi

Can someone tell me what should be the next step:

I have tried many ways but cannot seem to get the right answer.

This is what i have done:

$\displaystyle \begin{bmatrix}

1 & 2 & 1 & | & 6 \\

2 & -1 & -1 & |& -1\\

3 & 2 & 1 & | & 8

\end{bmatrix}$

2R1-R2 -> R2

3R1-R3 -> R3

$\displaystyle \begin{bmatrix}

1 & 2 & 1 & | & 6 \\

0 & 6 & 3 & |& 13 \\

0 & 4 & 2 & | & 10

\end{bmatrix}$

P.S