$A$ is a real $3 \times 3$ matrix and $b \in \mathbb{R}^{3}$. The RREF of the augmented matrix associated with the system $A x=b$ is $\left(\begin{array} {cccc}1 & 0 & 1 & 0 1 0 & 1 & 1 & -1 10 & 0 & 0& O\end{array} ight) $ Solve the system. Let $A$ be the matrix given in problem 1 . a. Find $\operatorname{Nul} A$. b. Find $\operatorname (Col} A^{T}$. CS.JG.080