2. A rectangular array of numeric or algebraic quantities subject to mathematical operations. The regular formation of elements into columns and rows.

4. In order to add or subtract matrices, the must have the same order. You add or subtract each entry in the first matrix with the corresponding entry in the second matrix. Your answer will be a matrix with the same dimensions as your original matrices.

7. A scalar is a constant being multiplied to a matrix. To perform scalar multiplication, multiply the scalar value by each entry in the matrix (similar to distribution)