Each matrix must be the same size (width & height must be the same)
[ 1 2 3 4 ] + [ 0 − 1 2 − 2 ] = [ 1 1 5 2 ] {\displaystyle {\begin{bmatrix}1&2\\3&4\end{bmatrix}}+{\begin{bmatrix}0&-1\\2&-2\end{bmatrix}}={\begin{bmatrix}1&1\\5&2\end{bmatrix}}}
M [ a , b ] × N [ c , d ] {\displaystyle M[a,b]\times N[c,d]}
b = c {\displaystyle b=c} (M's height equals N's width)
Resulting dimensions will be [ a , d ] {\displaystyle [a,d]}
[ 1 2 3 4 ] × [ 0 − 1 2 − 2 ] = [ ( 1 ∗ 0 ) + ( 2 ∗ 2 ) ( 1 ∗ − 1 ) + ( 2 ∗ − 2 ) ( 3 ∗ 0 ) + ( 4 ∗ 2 ) ( 3 ∗ − 1 ) + ( 4 ∗ − 2 ) ] = [ 4 − 5 8 − 11 ] {\displaystyle {\begin{bmatrix}1&2\\3&4\end{bmatrix}}\times {\begin{bmatrix}0&-1\\2&-2\end{bmatrix}}={\begin{bmatrix}(1*0)+(2*2)&(1*-1)+(2*-2)\\(3*0)+(4*2)&(3*-1)+(4*-2)\end{bmatrix}}={\begin{bmatrix}4&-5\\8&-11\end{bmatrix}}}
![{\displaystyle M[a,b]\times N[c,d]}](https://wikimedia.org/api/rest_v1/media/math/render/svg/db3fc0ba7982fcd98911fd3938b3e921047d3b7c)
(M's height equals N's width)
![{\displaystyle [a,d]}](https://wikimedia.org/api/rest_v1/media/math/render/svg/4be8d35e9f83b581f25f9def6f17d12a930362b1)
