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
答
2(a²-ab)-3(2/3a²-ab)
= 2a²-2ab-2a²+3ab
=ab
=-2x3
=-6
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