What you have is a linear equation in slope-intercept form. Linear equations in slope-intercept form will immediately provide you with all necessary information to graph them.
y = mx + b
where m = slope and b = y-intercept
Slope: -5
Y-Intercept: (0, 8)
Plot the point (0,8), and simply Rise/Run using the provided slope of -5 from there. Once you feel you have enough points, you can draw your line!
Example points:
0,8 + 1, -5 = (1, 3)
0,8 - 1, -5 = (-1, 13)
