Answer
See answers below
Work Step by Step
a) We obtain $\begin{bmatrix}
0 & 3 & 1\\
0 & -6 & -2\\
0 & 12 & 4
\end{bmatrix}\approx \begin{bmatrix}
0 & 3 & 1\\
0 & 0 & 0\\
0 & 0 & 0
\end{bmatrix} \approx \begin{bmatrix}
0 & 1 & \frac{1}{3}\\
0 & 0 & 0\\
0 & 0 & 0
\end{bmatrix} $
Since $n=3$, the basic for row space $A$ is $\{(0,3,1)\}$
b) We notice that the second column is independent. Hence, the basic for colspace $A$ is $\{3,-6,12)\}$
