These tables of ordered pairs represent some points on the graphs of lines p and r.

Line p
x y
-3 2
0 8
4 16

Line r
x y
-5 17
2 3
5 -3
Which system of equations is represented by lines p and r?

1. 3x-y=-12
7x+3y=21

2. 9x-4y=-9
2x+4y=15

3. 2x-y=-8
2x+y=7

4. x-2y=-8
6x+5y=30