(1/27)^x1 https://www.wolframalpha.com/input?i=%281%2F27%29%5Ex%3C3%5E%285x%E2%88%922%29+and+log%289%2C3%2Fx%29%3E1&lang=ja
(1/27)^x1
https://www.wolframalpha.com/input?i=%281%2F27%29%5Ex%3C3%5E%285x%E2%88%922%29+and+log%289%2C3%2Fx%29%3E1&lang=ja