They tell us that we go through the point (0,8) notice x is 0, so we're on the y-axis when x is zero, we're on the y-axis, so this is our y-interecept so b, we could say, we could do a couple of-- our y-intercept is the point (0,8), or we could say b, remember, it's also (0,b) we could say b=8