Differentiate both sides of (1) with respect to x:
(Identity (2) can also be proved using a combinatorial argument)
Now substitute x = 1 into (2). Then multiply both sides by 4 and you get the result.
This statement is FALSE. Substitute n = 1, for example, to see this.
The correct identity is given (and a solution suggested) in this thread: http://www.mathhelpforum.com/math-he...l-problem.html