Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)

$$x=3,\:y=4$$
Solving the system of equations using Matrices, we find: $$\begin{bmatrix}1&2&¦&11\\ 3&-1&¦&5\end{bmatrix}\\ \begin{bmatrix}1&0&¦&3\\ 0&1&¦&4\end{bmatrix}\\ x=3,\:y=4$$