Answer:
Think of y = mx + b,
With y = x + 3, m = 1 so the slope is one, and b = 3 which is the y-intercept, so plot the point (0,3) on the y-axis.
To find the next point to plot go up 1 and over to the right 1 because slope is rise over run.
With y = x, the slope is still 1, but there is no y-intercept, so you plot the point (0,0), and to find the next point on that line, go up 1 and over the right 1 because m=1
