先化简再求值 2(a²-ab)-3(2/3a²-ab),其中a=-2 b=3

问题描述:

先化简再求值 2(a²-ab)-3(2/3a²-ab),其中a=-2 b=3

 2(a²-ab)-3(2/3a²-ab)

= 2a²-2ab-2a²+3ab

=ab

=-2x3

=-6