Answer:
y = -2x + 12
Step-by-step explanation:
First, find the slope using rise over run (y2 - y1) / (x2 - x1)
Plug in the points:
(y2 - y1) / (x2 - x1)
(-12 - 18) / (12 + 3)
-30 / 15
= -2
Then, plug this and a point into y = mx + b and solve for b:
y = mx + b
-12 = -2(12) + b
-12 = -24 + b
12 = b
Then, plug in the slope and b into y = mx + b
y = -2x + 12 is the equation of the line
