-10n+2分之n(n-1)×4=54
问题描述:
-10n+2分之n(n-1)×4=54
答
-10n+2分之n(n-1)×4=54
则
-10n+2n²-2n=54
则
n²-6n-27=0
则
(n+3)(n-9)=0
则
n=-3或n=9