Use artificial variables to write a linear programming problem in canonical form with non-negative resource vector whose solution will determine whether there exists (and if so, find) non-negative reals $x1, x2, x3,$ and $x4$ such that $x1-x2+x3+x4=1$ and $x_1\begin{bmatrix}0 \\ 1\end{bmatrix} + x_2\begin{bmatrix}-2 \\ 0\end{bmatrix} + x_3\begin{bmatrix}1 \\ -2\end{bmatrix} + x_4\begin{bmatrix}0 \\ -1\end{bmatrix} = \begin{bmatrix}1 \\ -1\end{bmatrix}$. After setting up the problem, use the simplex method to solve it.
Can someone help me with this question? I'm not sure what it's exactly asking and I don't know how to approach it. I thought that the above two equations are the constraints?