I know there is a similar question in the website but it is wrong so do not copy that.

(5) Using the recurrence tree method, solve the following recurrence: T(n) = 2T (n/2) + n log2(n), where T(1) = 0(1). You do not have to draw the tree (you of course can, if you want). You can, instead, state clearly the sum of each level of the tree, and then rigorously bound the sum of each level using big oh notation