6pq-9+7pq^2-5pq+4+pq^2
Group like terms:7pq^2+pq^2+6pq-5pq-9+4Now group similar terms:7pq^2+pq^2+pq-5 (I subtracted 5pq from 6pq and added -9+4)8pq^2+pq-5 (This is your final answer since you cannot simplify any further)