Update README.md

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

Author: FabianaCampanari

README.md

@@ -273,7 +273,8 @@ The **graphical method** for solving simple linear programming (LP) problems inv
 
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-1. **[Plot the Constraints]():** For each constraint, treat it as an equality and plot the corresponding straight line on the Cartesian plane $\(x_1\)$ on the horizontal axis, $\(x_2\)$ on the vertical axis.
+1. **[Plot the Constraints]():** FFor each constraint, treat it as an equality and plot the corresponding straight line on the Cartesian plane ($x_1$ on the horizontal axis, $x_2$ on the vertical axis) [3].
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