Update cheatsheet.en.md

12.temporary_ins/90.electromagnetism-in-vacuum/10.maxwell-equations/20.overview/cheatsheet.en.md

@@ -503,7 +503,7 @@ I recognize here the law of conservation of charge.
 * *During an elementary displacement $`\overrightarrow{dl}`$* of the particle in the electromagnetic field
   $`\big(\overrightarrow{E}, \overrightarrow{B}\big)`$*, the **work of the Lorentz force** is written as :   
   <br>
-  **$`d\mathcal{W}_{Lorentz}=\overrightarrow{F}_{Lorentz}\cdot\overrightarrow{dl}`**,   
+  **$`d\mathcal{W}_{Lorentz}=\overrightarrow{F}_{Lorentz}\cdot\overrightarrow{dl}`$**,   
   <br>
   that is,   
   <br>