[tex]3)a)=log_3(27\cdot \frac{1}{3} )=log_39=log_33^2=2log_33=2\cdot1=2\\
b)=(3^4)^{ \frac{1}{4}}+( \frac{5}{1}) ^1=3+5=8\\
c)= \frac{5-3 \sqrt{2} }{5^2-(3 \sqrt{2} )^2} +\frac{5+3 \sqrt{2} }{5^2-(3 \sqrt{2} )^2} =\\
= \frac{10}{25-18} = \frac{10}{7} \\
4) =\sqrt{a} ( \frac{1}{3} - \frac{1}{a} )\cdot \frac{a }{ \sqrt{a}} =\\
= \frac{a-3}{3a} \cdot a= \frac{a-3}{3} [/tex]
