Update cheatsheet.fr.md

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

@@ -74,6 +74,17 @@ RÉSUMÉ<br>
   <br>
   $`\left.\dfrac{dN}{dt}\right\lvert_{\,\bigt}=r\,N(t)\quad \Longrightarrow\quad
    \left.\dfrac{dN}{N}\right\lvert_{\,\bigt}=r(t)\,dt`$
+
+  $`\begin{align}
+   \left.\dfrac{dN}{dt}\right\lvert_{\,\bigt} &=r\,N(t)\quad \Longrightarrow\quad
+   \left.\dfrac{dN}{N}\right\lvert_{\,\bigt}=r(t)\,dt\\
+   \\
+   &\Longrightarrow\quad
+   \left.\dfrac{dN}{N}\right\lvert_{\,\bigt}=r(t)\,dt
+   end{align}`$
+
+
+
   <br>
   $`\displaystyle\begin{align}
    \left.\dfrac{dN}{dt}\right\lvert_{\,\bigt}=r\,N(t)\quad &\Longrightarrow\quad