Log(3)x+log(9)x+log(81)x=7/4

ОДЗ х>0 [latex]\log_3x+\log_9x+\log_{81}x= \frac{7}{4} \\\\\log_3x+\log_3\sqrt{x}+\log_{3}\sqrt[4]{x}= \frac{7}{4}\\\\\log_3(x\cdot \sqrt{x}\cdot \sqrt[4]{x})= \frac{7}{4} \\\\ \log_3(x^{ \frac{7}{4} })= \frac{7}{4}\\\\ \frac{7}{4}\log_3x= \frac{7}{4} \\\\\log_3x=1\\\\x=3[/latex]