log3 x- log9 x+log81 x=3/4 ОДЗ x>0 log3 x - log3^2 x + log 3^4 x =3/4 log3 x -1/2 log3 x + 1/4 log x=3/4 log3 x (1-1/2+1/4)=3/4 3/4 log3 x=3/4 log3 x=1 x=3