Question 21966
{{{rise/run}}} is an explanation for the slope of a line.  
Imagine a little guy on the coordinate plane.  
For the line {{{y=(1/5)x}}}, the slope is rise 1 and run 5
{{{graph(300,200,-5,5,-5,5,(1/5)x)}}}
As you can see on the graph, a line crosses the graph lines every so often. 
So, put the guy at (0,0)
If he runs up one line, and runs right 5 lines, you get to an intersection point and if you keep on doing it, it'll keep on going forever.

Another example:
Line {{{y=(2/3)x}}}
What is the slope in terms of {{{rise/run}}}?
**no peeking**
Answer:
The little guy rises up 2 and runs 3. 
{{{graph(300,300,-5,5,-5,5,(2/3)x)}}}
Get it?
Hope this helps!