[tex]\begin{gathered} 6 \\ a) \\ \log (20) \\ 20=10\cdot2 \\ \text{log(20)}=\log (10\cdot2)=\log (10)+log(2)=1+0.3=1.3 \\ \log (20)=1.3 \\ \\ b) \\ \log _8(64) \\ 64=8^2 \\ \log _8(64)=\log _8(8^2)=2\log _8(8)=2\cdot1=2 \\ \log _8(64)=1 \\ \\ c) \\ \ln (6)=1.8 \\ \\ d)e^6=403.4 \end{gathered}[/tex]