IconVault's Matrix Calculator handles the linear algebra you do not want to do by hand. Enter matrices in editable grids and run add, subtract, multiply, transpose, determinant, inverse and linear system solving, with step-by-step workings shown so you can follow the computation, not just copy the answer.

Results are cleaned to readable precision, and everything runs fully in your browser with nothing uploaded. It is free to try (repeated use may ask for Pro), and it is great for checking homework, engineering problems and exam practice.