先化简,再求值3(a²-a+1)-2(a²+24+3)-(a²-8a)其中,a=-1

问题描述:

先化简,再求值3(a²-a+1)-2(a²+24+3)-(a²-8a)其中,a=-1

3(a²-a+1)-2(a²+2a+3)-(a²-8a)
=3a²-3a+3-2a²-4a-6-a²+8a
=a-3
=-1-3
=-4THANKS