Lets look at another example that will bring up some of the important details we must be able to deal with.[br][br]Consider the equation [math]y=\frac{2}{5}x-4[/math]
Ok, not too hard, but what if we had to do that by hand?[br]Its not very easy to make a good graph when the amounts are decimals.[br][br]So another way to graph this type of equation is to treat the slope as a two part rate.[br][br]Instead of the y-value changing by 0.4 for every x[br][br]We can leave it in fraction form and make one small change in the way we understand slope...[br][size=100]the y-value changes by 2 for every 5 x[/size]