Answer
See answers below
Work Step by Step
$\begin{bmatrix}
1 & -2 & 1 &3\\
3& -6 & 2 & 7\\
4 & -8 & 3 & 10
\end{bmatrix} \approx^1\begin{bmatrix}
1 & -2 & 1 &3\\
0& 0 & 1 & -2\\
0& 0 & 1 & -2
\end{bmatrix} \approx^2 \begin{bmatrix}
1 & -2 & 1 &3\\
0& 0 & 1 & 2\\
0& 0 & -1 & -2
\end{bmatrix} \approx^3 \begin{bmatrix}
1 & -2 & 1 &3\\
0& 0 & 1 & 2\\
0& 0 & 0 & 0
\end{bmatrix}$
Rank (A)= 2
The last matrix is in a row-echelon form.
$A_{12}(-3),A_{13}(-4)$
$M_2(-1)$
$A_{21}(-1),A_{23}(1)$
