Discrete mathematics

8. For each pair of proposition P and Q, state whether or not P Q. Show work. (5 points each)

(a)P =(pq)r,Q=p(qr)

(b) P = p q, Q = -p q

9. Determine whether each argument is valid. Show work (5 points each) (a) p(qr)q(pr)(pq)r