Law of Division

Theorem

Let $\mathbb F$ denote one of the following number systems:

rational numbers $\Q$
real numbers $\R$
complex numbers $\C$

Let $a, b \in \mathbb F$ such that $a \ne 0$.

Then there exists a unique $x$ such that:

$a x = b$

$x$ is then defined and denoted:

$x := b / a$