diff --git a/infotro/Eln/Filtres.md b/infotro/Eln/Filtres.md
index 6a4c604..b8bb5ef 100644
--- a/infotro/Eln/Filtres.md
+++ b/infotro/Eln/Filtres.md
@@ -96,15 +96,15 @@ $$F(s)=\frac{Y(s)}{U(s)}=\frac{d_{0}+d_{1}s+d_{2}s^{2}}{c_{0}+c_{1}s+c_{2}s^{2}}
 $$\begin{gather}
 C = c_{0}+\frac{2c_{1}}{T_{s}}+\frac{4c_{2}}{T_{s}^{2}} \\
 \\
-a_{1} = \frac{2\left( c_{0}-\frac{4c_{2}}{T_{s^{2}}} \right)}{C}
+a_{1} = \frac{2\left( c_{0}-\frac{4c_{2}}{T_{s}^{2}} \right)}{C}
 \qquad \qquad
-a_{2} = \frac{ c_{0}-\frac{2c_{1}}{T_{s}}+\frac{4c_{2}}{T_{s^{2}}} }{C}
+a_{2} = \frac{ c_{0}-\frac{2c_{1}}{T_{s}}+\frac{4c_{2}}{T_{s}^{2}} }{C}
 \qquad \qquad
 b_{0} = \frac{d_{0}+\frac{2d_{1}}{T_{s}}+\frac{4d_{2}}{T_{s}^{2}}}{C} \\
 \\
-b_{1} = \frac{2\left( d_{0}-\frac{4d_{2}}{T_{s^{2}}} \right)}{C}
+b_{1} = \frac{2\left( d_{0}-\frac{4d_{2}}{T_{s}^{2}} \right)}{C}
 \qquad \qquad
-b_{2} = \frac{d_{0}-\frac{2d_{1}}{T_{s}}+\frac{4d_{2}}{T_{s^{2}}}}{C}
+b_{2} = \frac{d_{0}-\frac{2d_{1}}{T_{s}}+\frac{4d_{2}}{T_{s}^{2}}}{C}
 \end{gather}$$
 
 ## Filtre numérique non-récursif (FIR)