According to WikiPedia
"Some languages do not support mixins on the language level, but can easily mimic them by copying methods from one object to another at runtime, thereby "borrowing" the mixin's methods. Note that this is also possible with statically typed languages, but it requires constructing a new object with the extended set of methods."
1) LinqExtensions static library functions ( .Where() ) applied to collections of regular objects (int) that implement IEnumerable do essentially this. They use a new object (LinqExtensions) to add the extended set of methods ( Where(),etc ).
Conclusion. LinqExtensions are mixins with all classes that support IEnumerable.
2) According to WikiPedia
"In object-oriented programming languages, a mixin is a class which contains a combination of methods from other classes. How such combination is done depends on language, but it is not by inheritance. If a combination contains all methods of combined classes it is equivalent to multiple inheritance."
By mixing ALL methods of classes that support IEnumerable ( List.HashCode, List.ToString, other List hierarchy baseline capabilities ), with ALL methods from the LinqExtensions static library ( .Where(), Max(), etc ) an equivalent to multiple inheritance is produced.
An equivalent to multiple inheritance is produced, yes or no?