2x+3y=1 and -3x+y=15 how do you get points (-4,3)

2x+3y=1 and -3x+y=15 how do you get points (-4,3)

$$\begin{array}{rrcl|lrcl} (1) & 2x+3y &=& 1 \quad & \quad (2)& -3x+y &=& 15 \quad | \quad * 3 \\ & & & \quad & \quad (2)& -9x+3y &=& 45 \\ \hline \end{array}$\\\\\\$ \small{\text{ $ \begin{array}{lrcl} (1)-(2): & 2x-(-9x) +3y -3y &=& 1-45 \\ & 11x &=& -44 \\ & \textcolor[rgb]{1,0,0}{x} &\textcolor[rgb]{1,0,0}{=}& \textcolor[rgb]{1,0,0}{-4} \\\\ \hline \\ (1) & 2(-4) + 3y &=& 1 \\ & -8 + 3y &=& 1 \\ & 3y &=& 9 \quad | \quad : 3\\ & \textcolor[rgb]{1,0,0}{ y} &\textcolor[rgb]{1,0,0}{=}& \textcolor[rgb]{1,0,0}{3} \end{array} $ }}$$