(1⼀2)×2!+(2⼀3)×3!+…+(2015⼀2016)×2016!=?

(1/2)×2!+(2/3)×3!+…+(2015/2016)×2016!=?
2025-02-26 18:26:42
推荐回答(1个)
回答1:

=1*1!+2*2!+...+2015*2015!

=2!-1!+3!-2!+....+2016!-2015!
=2016!-1