（a+2）²+|a-b+5|=0
根据平方和绝对值的性质得
a+2=0,a-b+5=0
a=-2,b=3
a+b=1,ab=-6
3a²b-[2a²b-（3ab-a²b-4a²）]-2ab
=3a²b-2a²b+3ab-a²b-4a²-2ab
=ab-4a²
=1-8
=-7当然确定啦