A matrix is a rectangular array of numbers arranged in rows and columns. It is used to represent systems of linear equations or to perform various operations such as addition, subtraction, and multiplication.
5 Must Know Facts For Your Next Test
The dimensions of a matrix are given by the number of rows by the number of columns (e.g., a 3x2 matrix).
Matrices can be added or subtracted only if they have the same dimensions.
Matrix multiplication is not commutative; that is, $AB \neq BA$ in general.
The identity matrix $I$ acts as the multiplicative identity for matrices, where $AI = IA = A$ for any matrix $A$ with compatible dimensions.
Gaussian elimination involves using row operations to transform a matrix into its row echelon form or reduced row echelon form.