a)
2+log_35=log_33^2+log_35=log_39+log_35=log_3(9*5)=log_345
b)
log_210-1=log_210-log_22=log_2(10:2)=log_25
c)
log_{\frac{1}{2}}6-2=log_{\frac{1}{2}}6-log_{\frac{1}{2}}(\frac{1}{2})^2=log_{\frac{1}{2}}6-log_{\frac{1}{2}}\frac{1}{4}=log_{\frac{1}{2}}(6:\frac{1}{4})=
=log_{\frac{1}{2}}(6*\frac{4}{1})=log_{\frac{1}{2}}24
d)
4-log_336=log_33^4-log_336=log_381-log_336=log_3\frac{81}{36}=log_3\frac{9}{4}