DOC: Improve docstring of Series.mul (pandas-dev#25136)

pandas/core/ops.py

@@ -459,14 +459,15 @@ def _get_op_name(op, special):
     Fill existing missing (NaN) values, and any new element needed for
     successful Series alignment, with this value before computation.
     If data in both corresponding Series locations is missing
-    the result will be missing
+    the result will be missing.
 level : int or name
     Broadcast across a level, matching Index values on the
-    passed MultiIndex level
+    passed MultiIndex level.
 
 Returns
 -------
-result : Series
+Series
+    The result of the operation.
 
 See Also
 --------
@@ -495,6 +496,27 @@ def _get_op_name(op, special):
 d    1.0
 e    NaN
 dtype: float64
+>>> a.subtract(b, fill_value=0)
+a    0.0
+b    1.0
+c    1.0
+d   -1.0
+e    NaN
+dtype: float64
+>>> a.multiply(b)
+a    1.0
+b    NaN
+c    NaN
+d    NaN
+e    NaN
+dtype: float64
+>>> a.divide(b, fill_value=0)
+a    1.0
+b    inf
+c    inf
+d    0.0
+e    NaN
+dtype: float64
 """
 
 _arith_doc_FRAME = """