Answer:
Step-by-step explanation:
It's a simple question as we know:
y-y1=m(x-x1)
y-20=12(x-3)
y=12x-36+20
y=12x-16
Now, your line is in slope intercept form you can compare it with
y=mx+c
m=12 and c=16. You can also put your point to verify your answer.