Left and Right Eigenvectors

If by "left eigenvalue" you mean a value of [itex]\lambda[/itex] such that
$Av= \begin{bmatrix}a & b & c \\ d & e & f \\ g & h & i\end{bmatrix}\begin{bmatrix}x \\ y \\ z\end{bmatrix}= \lambda \begin{bmatrix}x \\ y \\ z\end{bmatrix}$
and by "right eigenvalue", you mean a value of [itex]\lambda[/itex] such that
$vA= \begin{bmatrix}x & y & z\end{bmatrix}\begin{bmatrix}a & b & c \\ d & e & f \\ g & h & i\end{bmatrix}= \lambda \begin{bmatrix}x & y & z\end{bmatrix}$

Then the "right eigenvalues" of A are the "left eigenvalues" of the transpose of A.