3ab-2(a²-ab)-(a²-ab),其中(a-1)²+|b+1|=0 先化简后求值

3ab-2(a²-ab)-(a²-ab),其中(a-1)²+|b+1|=0 先化简后求值
3ab-2(a²-ab)-(a²-ab),其中(a-1)²+|b+1|=0 先化简后求值

3ab-2(a²-ab)-(a²-ab),其中(a-1)²+|b+1|=0 先化简后求值
(a-1)²+|b+1|=0
a-1=0、b+1=0
解得：a=1、b=-1
3ab-2(a²-ab)-(a²-ab)
=3ab-3(a²-ab)
=3ab-3a²+3ab
=6ab-3a²
=3a(2b-a)
=3×1×[2×(-1)-1]
=3×(-3)
=-9

3ab-2(a²-ab)-(a²-ab)=3ab-2a^2+2ab-a^2+ab=6ab-3a^2
(a-1)²+|b+1|=0,得a=1,b=-1.代入
6ab-3a^2=-6-3=-9

(a-1)²+|b+1|=0
a-1=0 a=1
b+1=0 b=-1

3ab-2(a²-ab)-(a²-ab)
=3ab-2a²+2ab-a²+ab
=-3a²+6ab
=-3x1²-6x1x1
=-3-6
=-9