Here is an explanation about drawing the graphs of linear lines which, I think, incorrect. So would you check it? "If graph, such as y=7x, goes through the origin, it has only one intercept, and other points will be needed for graphing." I think other points will not be needed because lines such as y=7x can easily be plotted. Source: Algebra and Trigonometry by Keedy/Bittinger 4th edition. Thank you.