First of all, the boundary line of the solution set is the line x + 3y = 6 so find where it crosses the axes (i) it crosses the x-axis where y = 0 i.e. at x = 6 (ii) it crosses the y-axis where x = 0 i.e. 3y = 6 or y = 2 . Plot those two points and draw a line through them (and byond them in both directions). since the inequation is </=, the line is included so draw a solid line (you would draw a broken line if the 6 was not included). Since you want x + 3y </= 6, you want all the page under the line so shade everything below the line.