题目内容
若等差数列满足,,则的值是 ( )
A.20 B.36 C.24 D.72
解析:C。本题考查了等差数列的性质, 因,得,,得,则, ,则
若等差数列满足,,则公差______;______.
(原创)若等差数列满足,,则的值是 ( )