Answer:
-2/3
Explanation:
First you need to find two exact points the use your formula. I used (0,1) and (-3,3).
y2-y1 / x2-x1
Or just use rise over run and count up 2 and across to the left 3 and also realize it's a negative slope going down from the left so your answer will be negative.
I hope I helped you. You can comment if you need anymore help.