1、先化简,再求值:6ab-3[3b²-(a²-2ab)+1],其中a=-2,b=-1/3
问题描述:
1、先化简,再求值:6ab-3[3b²-(a²-2ab)+1],其中a=-2,b=-1/3
答
原式=6ab-9b²+3(a²-2ab)-3
=6ab-9b²+3a²-6ab-3
=-9b²+3a²-3
=-1+12-3
=8