Update README.md

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

Author: FabianaCampanari

README.md

@@ -209,6 +209,20 @@ The **graphical method** for solving simple linear programming (LP) problems inv
      #### $$a_{i1}x_1 + a_{i2}x_2$$ = $$b_i$$
 
 
+  <br>
+
+
+  - Less than or equal to constraint:
+
+     #### $$a_{i1}x_1$$ + $$a_{i2}x_2 \leq b_i$$
+
+    <br>
+
+  - Greater than or equal to constraint:
+
+     #### $$a_{i1}x_1$$ + $$a_{i2}x_2 \geq b_i$$
+
+