What is the value of x in the following equation?
$$3 \log \frac{3}{5} - \log \frac{x}{21} + 2 \log \frac{25}{9} = 0$$
The above expression can be simplified as $$\log\ \ \frac{\ 27}{125}\times\ \ \frac{\ 21}{x}\times\ \ \frac{\ 625}{81}$$ = 0
On solving the same, we get $$\log\ \ \frac{\ 35}{x}=\ 0$$, for which x shall be 35, making $$\log1=\ 0$$