$\text{Terme - Additon - Subtraktion - Mulitiplikation - Division}\\ \displaystyle \frac{ x^4-3x^2-4}{ x^2-4} \
\small \begin{matrix} ( x^4&&-3x^2&&-4&):( x^2 -4 )= x^2 +1 \\
\,-( x^4&&-4x^2) \\ \hline
& x^2&&-4&\\
&&-( x^2&&-4) \\ \hline
&&&0\\
\end{matrix} \\ \normalsize \\ \\ \displaystyle \frac{ x^4-3x^2-4}{ x^2-4}= x^2+1$