Matrix Multiplication

$$\begin{bmatrix}
a & b \newline
c & d \newline
e & f
\end{bmatrix} \times
\begin{bmatrix}
y \newline
z \newline
\end{bmatrix} =
\begin{bmatrix}
a\times y + b\times z \newline
c\times y + d\times z \newline
e\times y + f\times z
\end{bmatrix}$$
3 by 2 matrix $\times$ 2 by 1 matrix $=$ 3 by 1 matrix

$m$ by $n$ matrix $\times$ $n$ by $o$ matrix $=$ $m$ by $o$ matrix