## Precalculus (6th Edition) Blitzer

Here we need to find $B+C$. Therefore consider, $B+C=\left[ \begin{array}{*{35}{l}} 0 & -2 \\ 3 & 2 \\ 1 & -5 \\ \end{array} \right]+\left[ \begin{matrix} 1 & 2 & 3 \\ -1 & 1 & 2 \\ -1 & 2 & 1 \\ \end{matrix} \right]$ This operation is not defined since only two matrices of the same order can be added; here, the size of matrix B is $3\times 2$ and the size of the matrix $C$ is $3\times 3$, so addition is not possible. Thus, the operation is not defined.