1)若A-B> 0,则A > B;
(2)若A-B=0 ,则A = B;
(3)若A-B< 0,则A < B.
4+3a²-2b+b²-﹙3a²-2b+1﹚
=4+b²-1
=b²+3≥3>0
∴4+3a²-2b+b²>3a²-2b+1