Update README.md

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

Author: FabianaCampanari

README.md

@@ -671,8 +671,18 @@ $3x_1 \leq 90
 ```latex
 x_1 \geq 0, \quad x_2 \geq 0
 ```
+<br>
 
+### 5. [Complete Mathematical Model]():
 
+### $\boxed{
+\begin{cases}
+\text{Maximize } Z = 120x_1 + 150x_2 \\
+2x_1 + 4x_2 \leq 100 \\
+3x_1 \leq 90 \\
+5x_1 + 3x_2 \leq 120 \\
+x_1 \geq 0, \quad x_2 \geq 0
+\end{ca$