Answer
See answers below
Work Step by Step
$\begin{bmatrix}
2 & 1\\
1 & -3
\end{bmatrix} \approx^1 \begin{bmatrix}
1 & -3 \\
2 & 1
\end{bmatrix} \approx^2 \begin{bmatrix}
1 & -3\\
0 & 7
\end{bmatrix} \approx^3 \begin{bmatrix}
1 & -3\\
0 & 1
\end{bmatrix}$
Rank (A) =2
The rank of each matrix:
$P_{12}$
$A_{12}(-2)$
$M_2(\frac{1}{7})$
