Update README.md

Signed-off-by: Fabiana 🚀  Campanari <113218619+FabianaCampanari@users.noreply.github.com>

Author: FabianaCampanari

README.md

@@ -225,8 +225,11 @@ The **graphical method** for solving simple linear programming (LP) problems inv
 
   - [Less than or equal to constraint]():
 
-  $$a_{i1}x_1$$ + $$a_{i2}x_2 \leq b_i$$
+   $$a_{i1}x_1$$ + $$a_{i2}x_2 \leq b_i$$
 
+   ```latex
+   a_{i1}x_1 + a_{i2}x_2 \leq b_i
+   ```
     <br>
 
   - [Greater than or equal to constraint]():