Rules for Adding and Subtracting Matrices
Part of the Pre-Calculus Workbook For Dummies Cheat Sheet
To add or subtract matrices, you have to operate on their corresponding elements. In other words, you add or subtract the first row/first column in one matrix to or from the exact same element in another matrix. The two matrices must have the same dimensions; otherwise, an element in one matrix won't have a corresponding element in the other.