Different ones represent unique linear transformations.
Certain types of these entities have characteristic functions, which can help in finding the eigenvalues and traces of these entities. Different ones represent unique linear transformations., and operations on them include "transpose." One quantity associated with them can solve linear equations with Cramer's Rule; that quantity, the determinant, is equal to A times D minus B times C in a "square" one of these. For 10 points, name these rectangular arrays of numbers.
Certain types of these entities have characteristic functions, which can help in finding the eigenvalues and traces of these entities.
{matrix} or {matrices}