Update cheatsheet.fr.md

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

@@ -80,7 +80,7 @@ RÉSUMÉ<br>
    \;\;&\Longrightarrow\quad\left.\dfrac{dN}{N}\right\lvert_{\,\bigt}=r\,dt\\
    \\
    &\Longrightarrow\;\underbrace{\int_{N(t_1)}^{N(t_2)}\dfrac{dN}{N}}_{\begin{array}{c}
-   \\text{Primitive }\big(\dfrac{dx}{x}\big)\\ =\;ln\,|\,x\,|\end{array}}=\int_{t_1}^{t_2} r\,dt\\
+   \text{Primitive }\big(\frac{dx}{x}\big)\\ =\;ln\,|\,x\,|\end{array}}=\int_{t_1}^{t_2} r\,dt\\
    \\
    &\Longrightarrow\;\big[\,ln\,|N|\,\big]_{N(t_1)}^{N(t_2)}= r \,\big[\,t\,\big]_{t_1}^{t_2}\\
    \\