Answer:
the graph's slope-intercept is 3 or 3/1. you do this by finding the rise over run (how many squares does it go up, and how many does it go over).
The Y-intercept is -2. You can always find this by using the formula y= mx + b. Whatever number is in the place of "b" is the y-intercept.
I'm going to take a guess and say you're in Algebra 1. Either that or Pre-Algebra. This stuff took me a little while to full grasp, so don't worry! YOu'll understand it soon enough!