Answer:
y = 3m - 6
Explanation:
y = mx + b
b is the point where the line cuts the y axis.
That happens at (0,-6)
So far what you have on this equation is
y = mx - 6
You could use the point that cuts the x axis to find m.
y = 0
x = 2
0 = m*2 - 6 Add 6 to both sides
6 = m*2 - 6 + 6
6 = 2*m Divide by 2
6/2 = 2m/2 Do the division
3 = m
Answer
y = 3m - 6