m=-2 and b=3
Step-by-step explanation:
One way to find slope is to use rise over run (most useful when there is a graph). First find any two points along the line where it intersects with a point on the grid. (1,1); (2,-1) and (3,-3) are some examples. Then count how many spaces vertically and then horizontally it takes to get to the next point. In this case it is two spaces down (rise) and 1 space right (run). So rise/run = 2/1 =2. That is your slope. Because it is pointing downwards or decreasing we know it is a negative slope.
The y-intercept is just where the line intercepts with the y-axis. In other words, when x=0 what does y equal? Here it is 3.