|a-2|+(b+3)²=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
3a²b-[2ab²-2(ab-1.5a²b)+ab]+3ab²
=3a²b-(2ab²-2ab+3a²b+ab)+3ab²
=3a²b-(2ab²-ab+3a²b)+3ab²
=3a²b-2ab²+ab-3a²b+3ab²
=ab²+ab
=ab(b+1)
=2×(-3)×(-3+1)
=12