1. $(-1,2)$
2. $(-4,3)$
3. $(-1,-3)$
4. $(-3,1)$
5. Parallel lines $\therefore$ no intersection
6. $(-2,-2)$
7. $(-3,1)$
8. $(1,-2)$
9. $(-3,-1)$
10. Parallel lines $\therefore$ no intersection
11. $\phantom{a}$
$\begin{array}[t]{rrrrrrrrrr} x&+&3y&=&-9\hspace{0.25in}&5x&+&3y&=&3 \\ -x&&&&-x\hspace{0.25in}&-5x&&&&-5x \\ \hline \dfrac{3y}{3}&=&\dfrac{-x}{3}&-&\dfrac{9}{3}\hspace{0.25in}&\dfrac{3y}{3}&=&\dfrac{-5x}{3}&+&\dfrac{3}{3} \\ \\ y&=&-\dfrac{1}{3}x&-&3\hspace{0.25in}&y&=&-\dfrac{5}{3}x&+&1 \\ \\ (3,-4)&&&&&&&&& \end{array}$
12. $\phantom{a}$
$\begin{array}[t]{rrrrrrrrrr} x&+&4y&=&-12\hspace{0.25in}&2x&+&y&=&4 \\ -x&&&&-x\hspace{0.25in}&-2x&&&&-2x \\ \hline \dfrac{4y}{4}&=&\dfrac{-x}{4}&-&\dfrac{12}{4} \hspace{0.25in}&y&=&-2x&+&4 \\ \\ y&=&-\dfrac{1}{4}x&+&3 \hspace{0.25in}&y&=&-2x&+&4 \\ \\ (4,-4)&&&&&&&&& \end{array}$