根据(a+b)²+|2b-1|=0
得 a+b=0 2b-1=0
解得 b=1/2 a=-1/2
ab-【2ab-3(ab-1)】
=ab-[2ab-3ab+3]
=ab-[-ab+3]
=ab+ab-3
=2ab-3
=2*(-1/2)*1/2-3
=-1/2-3
=-3又2分之1
根据(a+b)²+|2b-1|=0
得 a+b=0 2b-1=0
解得 b=1/2 a=-1/2
ab-【2ab-3(ab-1)】
=ab-[2ab-3ab+3]
=ab-[-ab+3]
=ab+ab-3
=2ab-3
=2*(-1/2)*1/2-3
=-1/2-3
=-3又2分之1