Условие:

1) log7 (x - 1) log7(x) =log7(x);

2) log1/3(x)log1/3(3x - 2) = log1/3(3x - 2);

3) log2 (3x + 1) log3(x) = 2log3(3x+1);

4) log корень 3(x - 2) log5(x)= 2log3(x - 2)