Work Step by Step
When an equation is in slope-intercept form, or y=mx+b form, m=slope and b=y-intercept. If a line is horizontal, then it has a slope of 0. Therefore, y=(0)x+b=0+b=b The y-intercept is the y value where x=0, and since this line has a slope of 0 and passes through the point (8, 4) it also passes through the point (0, 4), because the line is horizontal. Therefore, the y-intercept=4.