- Thread starter
- #1

$$

\begin{vmatrix}

a & b+c & 1\\

b & a+c & 1\\

c & a+b & 1

\end{vmatrix} =

\begin{vmatrix}

a & b & 1\\

b & a & 1\\

c & a & 1

\end{vmatrix} +

\begin{vmatrix}

a & c & 1\\

b & c & 1\\

c & b & 1

\end{vmatrix}

$$

In this example this works but I don't know if this just a coincidence.