Write each of the expressions as a simple number:

1. $$2{\log }_{12}(3)+4{\log }_{12}(2)$$
2. $$3{\log }_6(3)-3{\log }_6\left(\frac{1}{2}\right)$$
3. $${\log }_3\left(\frac{\lambda }{9}\right)+{\log }_3\left(\frac{3}{\mu }\right)-{\log }_3\left(\frac{\lambda }{\mu }\right)$$