5a的n次方-8a的a+1次方+(-2a的n次方)+6a的n次方-a的a+1次方=
问题描述:
5a的n次方-8a的a+1次方+(-2a的n次方)+6a的n次方-a的a+1次方=
答
5a n -8aa+1 +(-2an)+6an -a a+1
=5a n -2an+6an -8aa+1 -a a+1
=9a n -9aa+1
=9(a n -a a+1)