先化简,在求值:(a+1)(a-1)+a(a-2),其中a=1
问题描述:
先化简,在求值:(a+1)(a-1)+a(a-2),其中a=1
答
先化简,在求值:(a+1)(a-1)+a(a-2),其中a=1
(a+1)(a-1)+a(a-2)
=a²-1+a²-2a
=2a²-2a-1
=2-2-1
=-1