First, you have to find the slope of graph so you find the rise over run Y/X. Since the X values are being measured by 1’s, and the Y values are being measure by 5’s, your slope would be -5 (not 5 as the graph line is decreasing therefore it is negative). To find b, you find the Y intercept of the graph (where Y is when X=0) and in this case, the y intercept is 30. So the equation that describes what is occurring in the graph is Y=-5x+30 as a linear equation is written as Y=mx+b. You can check If the equation is correct by substituting the x and y values of a specific coordinate point on the graph. For example: 25= -5(1)+30. This gives you 25=25 so the equation is correct.
