diff --git a/tpEdo/tpEquadiffs.md b/tpEdo/tpEquadiffs.md
index 15487d7ad18871866826c5d0c4827acfef129f1e..edbfbc5f0cd108f7d3dc6e8e12445ee05c52b5fe 100644
--- a/tpEdo/tpEquadiffs.md
+++ b/tpEdo/tpEquadiffs.md
@@ -153,8 +153,8 @@ S(t=0)=S_0,\quad E(t=0)=E_0,\quad I(t=0)=I_0,\quad R(t=0)=R_0,
 $$
 et par quatre équation différentielles ordinaires
 \begin{align}
-S'(t)&=-\frac{\mathcal{R}_0}{T_{inf}}I(t)S(t),\\
-E'(t)&=\frac{\mathcal{R}_0}{T_{inf}}-\frac{1}{T_{inc}E(t)},\\
+S'(t)&=-\frac{\mathcal{R}_0}{T_{inf}}I(t)\frac{S(t)}{N},\\
+E'(t)&=\frac{\mathcal{R}_0}{T_{inf}}I(t)\frac{S(t)}{N}-\frac{1}{T_{inc}E(t)},\\
 I'(t)&=\frac{1}{T_{inc}E(t)}-\frac{1}{T_{inf}}I(t),\\
 R'(t)&=-\frac{1}{T_{inf}}I(t),
 \end{align}