You can put this solution on YOUR website! Graph y = 3x, this is a line, since it's a linear equation, in order to graph a line you need a two points on that line
substitute x=0, then y=3*0=0, now you have first point (0,0)
substitute x=1, then y=3*1=3, now you have second point (1,3)
plot the points and connect the dots