Update cheatsheet.fr.md

12.temporary_ins/32.sets-systems/30.n3/20.systems/20.overview/cheatsheet.fr.md

@@ -98,7 +98,7 @@ RÉSUMÉ<br>
 
   <br>
 
-   $`\Large{\left.\dfrac{dN}{dt}\right\lvert_{\,\bigt} = r\,N(t)}\quad \Longrightarrow\quad\left.\dfrac{dN}{N}\right\lvert_{\,\bigt}=r\,dt`$
+   $`\Large{\left.\dfrac{dN}{dt}\right\lvert_{\,\bigt}} = r\,N(t)}\quad \Longrightarrow\quad\left.\dfrac{dN}{N}\right\lvert_{\,\bigt}=r\,dt`$
 
   $`\displaystyle\begin{align}
   \quad &\Longrightarrow\quad\int_{N(t_1)}^{N(t_2)}\dfrac{dN}{N}=\int_{t_1}^{t_2} r\,dt\\