Update README.md

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

Author: FabianaCampanari

README.md

@@ -2035,7 +2035,7 @@ v_1 &= 12, \quad v_2 = 18, \quad v_3 = 24 \\
 
 | Non-Basic Variable | Reduced Cost                | Value  |
 |--------------------|-----------------------------|--------|
-| $ x_{12} $         | $ 0 + 18 - 22 = -4 $        | $-4$   |
+| $x_{12}$           | $0 + 18 - 22 = -4$          | $-4$   |
 | $ x_{13} $         | $ 0 + 24 - 30 = -6 $        | $-6$   |
 | $ x_{23} $         | $ 6 + 24 - 32 = -2 $        | $-2$   |
 | $ x_{32} $         | $ 10 + 18 - 15 = 13 $       | $13$   |