jika x=p2 - pq +3q2 dan y=p2+2pq-q2 tentukan hasil dari : a. x -2y: b.2x-y: c.3x -2y:

A. x-2y
=p²-pq+3q²-2(p²+2pq-q²)
=p²-pq+3q²-2p²-4pq+2q²
= -p²-5pq+5q²
B. 2x-y
=2(p²-pq+3q²)-(p²+2pq-q²)
=2p²-2pq+6q²-p²-2pq+q²
=p²-4pq+7q²
C. 3x-2y
=3(p²-pq+3q²)-2(p²+2pq-q²)
=3p²-3pq+9q²-2p²-4pq+2q²
=p²-7pq+11q²