Solution (source code)

= Solution

For a square <matrix>, the corresponding changes in its <determinant> are
$$
\boxed{\begin{aligned}
R_i\leftrightarrow R_j &: \quad \det\longmapsto-\det,\\
R_i\leftarrow cR_i &: \quad \det\longmapsto c\det,\\
R_i\leftarrow R_i+cR_j &: \quad \det\longmapsto\det.
\end{aligned}}
$$
These follow respectively from the alternating property, <multilinearity> in the rows, and the fact that a <determinant> with two equal rows vanishes.