A linear equation is an algebraic equation of the form
 |
involving only a constant and a first-order (linear) term, where 
is the slope and 
is the 
-intercept. The above form is aptly known as slope-intercept
form; alternatively, linear equations can be written in a number of other forms
including standard form, intercept
form, etc.
Occasionally, the above is called a "linear equation of two variables," where 
and 
are the variables. Equations such as 
and 
are linear equations of a single variable, and 
is an example of a linear equation with three variables.
