# Quick Access

# Introduction

**The linear equation is the simplest form of equation you may deal with**;
it restricts the problem to a unique unknown variable (usually called
**x**) and no exponent (e.g. f(x) = 2x + 15).

The general form of such an equation is: $$\textbf{f(x) = ax + b}$$

Any linear expression can be drawn as a **line in a 2D graphic**.
The graph drawing is straightforward: we have y, or f(x), on the vertical axis (the result)
and for a range of x values (horizontal abscissa) we compute and
**plot the points (x, y).**

In brief:Changing a is changing the slope of the line.Changing b is changing the offset of the line.