To find your slope (or m value), you must identify 2 points that your line crosses through (I used (1,1) and (0,6). You can either count up and over to the point (0,6) from (1,1), or you can use the formula y2-y1/x2-x1 (it would look like 6-1/0-1). This will give you -5 for your slope.
Your x-intercept (or b value) is 6 because you can see from the graph that that is where your line intercepts y.
