First you'll use the slop formula to find the slope.
Slope = [tex] \frac{y2-y1}{x2-x1} [/tex]
Slope = [tex] \frac{0-9}{3-0} [/tex]
Slope = [tex] \frac{-9}{3} [/tex]
Slope = [tex] {-3} [/tex]
Now we write the equation.
y = mx + b
y = -3x + 9
In this equation -3 is the slope and 9 is the y-intercept.
Hope this helps :)
