The Attempt at a Solution
I just need help knowing what Re means. I've never seen it before and the prof didn't mention it.
<v,w> is going to be some complex number. take its real part.
<(2+3i,4-5i),(3,1-i)> = (2+3i)(3) + (4-5i)(1+i) = 6+9i + (4-(-5) + (4 - 5)i)
= 6+9i + 9-i = 15+8i, and the real part of this is 15.