Linear Algebra - System of Linear Equations

Consider the system of linear equations: $Ax = b$, where $A$ is an $n \times n$ matrix, and $x$ and $b$ are $n$-dimensional column vectors. Suppose this system of equations has a unique solution. Which of the following s...

Let $A = \begin{bmatrix} 1 & 1 & 1 \\ -1 & -1 & -1 \\ 0 & 1 & -1 \end{bmatrix}$ and $b = \begin{bmatrix} 1/3 \\ -1/3 \\ 0 \end{bmatrix}$. Then, the system of linear equations $Ax = b$ has