Dimensions

The number of rows and the number of columns in a matrix. For example,
a
3×4
dimensional matrix has 3 rows and 4 columns.
Elementary Row Operations

There are three elementary row operations:
 Multiplying a row by a constant.
 Switching two rows.
 Adding a constant times a row to another row.
Identity Matrix

The matrix
Which, when multiplied by any matrix, does not change the matrix. In
other words, any matrix multiplied by
I
is equal to itself.
Matrix

A way of representing data in a rectangular array.
Reduced RowEchelon Form

The form of a matrix in which the first
m×m
entries form the
identity matrix:
Row Reduction

The process through which a matrix is converted to reduced rowechelon
form, using elementary row operations.
Scalar

A single constant, variable, or expression.