网址:http://m.1010jiajiao.com/timu3_id_558750[举报]
若等差数列的各项依次递减,且a2a4a6=45,a2+a4+a6=15,则数列{an}的通项公式为( )?
A.2n-3 B.-2n+3
C.-2n+13 D.2n+9