若x，y∈R，且x+2y=3，则3x+9y的最小值是

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SQL Error: select id,body,options from ***_enewstiku_ where sourceid='15532' and id < 2638727 and id<>'2638727' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='15532' and id > 2638727 and id<>'2638727' order by id asc limit 5