Update 3_vector_spaces.md

src/3_vector_spaces.md

@@ -74,9 +74,9 @@ You might be familiar with the concept that one can perform a number of **operat
   Addition and scalar multiplication of vectors are both {\bf associative} and {\bf distributive}, so the following
   relations hold
   
-  - $$(\lambda \mu) \vec{a} = \lambda (\mu \vec{a}) = \mu (\lambda \vec{a})$$
-  - $$\lambda (\vec{a} + \vec{b}) = \lambda \vec{a} + \lambda \vec{b}$$
-  - $$(\lambda + \mu)\vec{a} = \lambda \vec{a} +\mu \vec{a}$$
+  1. $$(\lambda \mu) \vec{a} = \lambda (\mu \vec{a}) = \mu (\lambda \vec{a})$$
+  2. $$\lambda (\vec{a} + \vec{b}) = \lambda \vec{a} + \lambda \vec{b}$$
+  3. $$(\lambda + \mu)\vec{a} = \lambda \vec{a} +\mu \vec{a}$$
 
 - **Vector product**: in addition to multiplying a vector by a scalar, as mentioned above, one can also multiply two vectors among them.
   There are two types of vector productions, one where the end result is a scalar (so just a number) and