You can put this solution on YOUR website! the scale on your graph should be determined by the maximum value you expect for the dependent variable and for the independent variable.
if the increments on the x-axis are 1 and you expect the value of x to go from -10 to 10, then your scale on the x-axis is -10 to 10.
the increments on the y-axis are determined by the value of the equation at the extremes of the x-axis.
if the equation is y = 100*x, then when x = -10, y will be equal to -1000, and when x = +10, y will be equal to +1000
your scale on the y-axis should therefore be -1000 to 1000.
you should always add a few units so that the maximum values are not exactly at the edge of the graph.
in the example above, you might set the x-axis from -15 to 15 and the y-axis from -1500 to 1500.
that allows the full measure of the graph to be centered on the graph paper without crowding the edges.
the graph of what I just showed you would look like this:
if you are manually drawing the graph, you have more control over the units to be displayed.
for example, I would have picked the y-units to be displayed every 100 units.
