Question

not (p and q); (not p) and (not q)

Answer 1

Are the two statements logically equivalent?

Answer 2

No.
Check out DeMorgan's Law:

http://regentsprep.org/Regents/math/geometry/GP1/negatecompound.htm

Answer 3

what about: (p or q) or r; p or (q or r)

Answer 4

I'm not sure about those. You may need to make truth tables to decide.

Answer 5

it is true
... Thanks for your help