a-2|+(b+3)�0�5=0 两个非负数的和为0,则他们都等于0
a-2=0 b+3=0 解得
a=2 b=-3
3a�0�5b-[2ab�0�5-2(ab-1.5a�0�5b)+ab]+3ab�0�5
=3a�0�5b-(2ab�0�5-2ab+3a�0�5b+ab)+3ab�0�5
=3a�0�5b-(2ab�0�5-ab+3a�0�5b)+3ab�0�5
=3a�0�5b-2ab�0�5+ab-3a�0�5b+3ab�0�5
=ab�0�5+ab
=ab(b+1)
=2×(-3)×(-3+1)
=12