Now we're ready to look at several extensions of the distributive law.
Recall that the ‘basic model’ of the distributive law is:
for all real numbers
$\,a\,$, $\,b\,$, and $\,c\,$,
$\,a(b+c) = ab + ac\,$.
There may be more than two terms in the parentheses:
All the usual rules for dealing with signed terms hold.
For example,
In each term, variables must be written in the order they appear, from left-to-right, in the original expression.