<prompt> Acha a, b, c ziwe nambari halisi chanya kiasi kwamba a b c 1. Pata thamani ya chini zaidi yafrac1a 2b frac1b 2c frac1c 2a.  <response>: Na AM-HM,fraca 2b b 2c c 2a3 ge frac3frac1a 2b frac1 b 2c frac1c 2a,hivyofrac1a 2b frac1b 2c frac1c 2a ge frac93a 3b 3c frac93 3. Usawa hutokea wakati a b c frac13, hivyo thamani ya chini ni 3. 