This is like the other question I posted. I get so confused when they start talking about u + v and all these variables. Give me #'s and I'm good. But Variables throw me off for some reason. Anyway, I can't figure this out either

Let u and v be distinct vectors in R^n. Prove that {u,v} is linearly independent if and only if {u+v, u-v} is linearly independant.

TIA!!!!