diff --git a/00.brainstorming-pedagogical-teams/40.collection-existing-pedagogical-content/40.classical-mechanics/10.main/textbook.fr.md b/00.brainstorming-pedagogical-teams/40.collection-existing-pedagogical-content/40.classical-mechanics/10.main/textbook.fr.md
index 92a726e0f..755755ece 100644
--- a/00.brainstorming-pedagogical-teams/40.collection-existing-pedagogical-content/40.classical-mechanics/10.main/textbook.fr.md
+++ b/00.brainstorming-pedagogical-teams/40.collection-existing-pedagogical-content/40.classical-mechanics/10.main/textbook.fr.md
@@ -291,19 +291,6 @@ y'=y-V_y\,t \\
 z'=z-V_z\,t 
 \end{array}\right.}`$
 
-$`\mathbf{\left\{} \begin{array}{l}
-\mathbf{t'=t} \\
-\mathbf{x'=x-V_x\,t} \\
-\mathbf{y'=y-V_y\,t} \\   
-\mathbf{z'=z-V_z\,t} 
-\end{array}\right.}`$
-
-$`\left\{ \mathbf{\begin{array}{l}
-t'=t \\
-x'=x-V_x\,t \\
-y'=y-V_y\,t \\   
-z'=z-V_z\,t 
-\end{array}\right.}`$
 
 *CLAPTMEC-FU-040* : 
 [ES] teorema de la suma de velocidades