\[ E=mc^2 \]
\[ a^2 + b^2 = c^2 \]
\[ H_2O \]
\[ NH_3 \]
\[ \log_7{49} = 2 \]
\[ \log_6{216}=3 \]
\[ \log_3{81}=4 \]
\[ \begin{matrix} 12 & 14 & 10 \\ 19 & 20 & 12 \\ 10 & 18 & 10 \end{matrix} \]
\[ \begin{pmatrix} 9 & 8 & 12 \\ 10 & 9 & 9 \\ 7 & 8 & 10 \end{pmatrix} \]
\[ \begin{vmatrix} 9 & 17 & 14 \\ 7 & 5 & 19 \\ 18 & 20 & 21 \end{vmatrix} \]