MathGloss/M/Matrix addition

Examples
Let $$A=\begin{pmatrix} 1 & 3 &-4 \\ 0 & -1 & 5 \\  3 & 4 & 8 \end{pmatrix}$$

and $$B=\begin{pmatrix} 1 & 0 & 2 \\ 1 & 2 & 5 \\  0 & 4 & 6 \end{pmatrix}$$

Then $$C=A+B$$ is

$$C=\begin{pmatrix} 2 & 3 &-2 \\ 1 & 1 & 10 \\  3 & 8 & 14 \end{pmatrix}$$