]>

(\begin{matrix} 1 \\ 2 \end{matrix}) + (\begin{matrix} 3 \\ 4 \end{matrix}) = (\begin{matrix} 4 \\ 6 \end{matrix})

[\begin{matrix} a \\ b \\ c \end{matrix}] \cdot [\begin{matrix} e f g \end{matrix}] = a e + b f + c g

(\begin{matrix} 1 & 2 & 3 \\ 4 & 5 & 6 \\ 7 & 8 & 9 \end{matrix}) + (\begin{matrix} 3 & 2 & 1 \\ 6 & 5 & 4 \\ 9 & 8 & 7 \end{matrix})

(\begin{matrix} 1 & 2 & 3 \\ 4 & 5 & 6 \\ 7 & 8 & 9 \end{matrix}) \cdot (\begin{matrix} x \\ y \\ z \end{matrix}) = (\begin{matrix} 0 \\ 0 \\ 0 \end{matrix})

\det (A) = | \begin{matrix} a & b & c \\ d & e & f \\ g & h & i \end{matrix} | = a (e i - f h) + b (f g - d i) + c (d h - e g)

{\begin{matrix} y = 0, x < 0 \\ y = 2, x = 0 \\ y = x^{2}, x > 0 \end{matrix}