<u+ v, w>= <u,w>+ <v,w>
<au, v>= a<u, v>
if the vector space is over the complex numbers (the overline is the complex conjugate).
Using those, and now you can use the fact that and are orthonormal.
Apply that to your problem. Tedious but straightforward.
(I just re-read the problem and noticed that the set of "v" vectors in the definition of w1 and w2 are disjoint! Gosh this problem is trivial!)