Matrix division does not denote a single operation having all the properties of scalar division. If
is an invertible square matrix, one common convention
defines right division and left division respectively by
These expressions generally differ because matrix multiplication is not commutative. More broadly,
solving
or
is preferable to explicitly forming an inverse. A rectangular system has a rectangular
matrix of coefficients, while a singular system
has a singular matrix and no ordinary inverse.
Such linear systems may instead be treated
using a pseudoinverse or least
squares solution.