Answer
See answers below
Work Step by Step
a) $\begin{bmatrix}
2&-7\\
-4& 14
\end{bmatrix} \approx^1
\begin{bmatrix}
2&-7\\
0&0
\end{bmatrix} \approx^2 \begin{bmatrix}
1&-\frac{7}{2}\\
0& 0
\end{bmatrix}$
$1.A_{12}(2)$
$2.M_1(\frac{1}{2})$
b) $rank(A)=1$
c) Since $rank(A)=1 \lt 2$, A is not invertible
