Abstract In linear algebra,
Cramer's rule is an explicit formula for the solution of a system
of linear equations with as many equations as unknowns, that is,
for the solution of a system with a square matrix. In this paper
we want to generalize this method for an $m \times n$ system of
linear equations, such that $m < n$. We offer a simple and
convenient formula for systems with rectangular matrices using
only the minors of the augmented matrix, as well as the usual
method of Cramer. We also generalize the results in order to solve
a matrix equation.
