Find a start point (or the one the gave you (3,2)) and then follow the line to the next point that crosses exactly over where to points cross (where poth x and y would be whole numbers) count how many times the point moved up, then how many time it moved left. Put the first over the second in fraction form and there is your slope.
In order to find the slope, you need to find the difference in the x values and the difference in the y values. To do this, you write out y2-y1/x2-x1, insert your x and y values, and get your answer. Then, you find your y-intercept (where the x value is 0).
