P1 = (-8, -3)
P2 = (-12, -3)
slope = m = (y2 - y1) / (x2 - x1)
Substitution
m = (-3 + 3 ) / (-12 + 8)
Simplification
m = 0 / -4
Result
m = 0
P1 = (7, -9)
P2 = (15, -29)
slope = m = (-29 + 9) / (15 - 7)
m = -20/8
m = -10/4
m = -5/2
This is the graph
ok
2x + 2y = 4
2y = -2x + 4
y = -2/2x + 4/2
y = -x + 2