Drawing linear functions

Given is a linear function equation:

The graph of a linear function is a straight line, so you need two points to draw.

1. A point of the line is already given by the y-intercept $n$: $P(0|n)$.


2. Another point can be found using the slope $m$:
   
   If $m$ is a fraction, for example $m=\frac{ a }{ b }$, one moves from the point $P(0|n)$ $b$ units to the right and $a$ units upward.
   If $m$ is not a fraction then one can think of a $1$ in the denominator.
   
   With a negative increase (minus in front of the $m$) one goes down $a$ units.


3. Now draw a straight line through both points.