Slope intercept form is given by:
y = mx + b
where:
m = slope
b = y-axis intercept
Let's find the slope m using the following formula:
m = (y2 - y1)/(x2-x1)
Where:
(x1,y1) = (9,2)
(x2,y2) = (-3, -2)
m = (-2 - 2)/(-3 - 9) = -4/-12 = 1/3
Now, lets use the point slope formula:
y - y1 = m(x - x1)
y - 2 = 1/3(x - 9)
Solving for y:
y - 2 = x/3 - 3
y = x/3 - 3 + 2
y = x/3 - 1