Answer :
[tex]Use:\\logb^c=c\cdot log b\\\\log(a\cdot b)=loga+logb\\\\==================================[/tex]
[tex]5)\\log270=log(27\cdot10)=log27+log10=log3^3+1=3log3+1=\boxed{3u+1}\\\\or\\=log27+log10=log(3\cdot9)+1=log3+log9+1=\boxed{u+s+1}[/tex]
[tex]6)\\log99=log(9\cdot11)=log9+log11=log3^2+t=2log3+t=\boxed{2u+1}\\or\\=log9+log11=\boxed{s+t}[/tex]
[tex]7)\\log121=log11^2=2log11=\boxed{2t}[/tex]
[tex]8)\\log363=log(121\cdot3)=log121+log3=log11^2+u=2log11+u=\boxed{2t+u}[/tex]
[tex]5)\\log270=log(27\cdot10)=log27+log10=log3^3+1=3log3+1=\boxed{3u+1}\\\\or\\=log27+log10=log(3\cdot9)+1=log3+log9+1=\boxed{u+s+1}[/tex]
[tex]6)\\log99=log(9\cdot11)=log9+log11=log3^2+t=2log3+t=\boxed{2u+1}\\or\\=log9+log11=\boxed{s+t}[/tex]
[tex]7)\\log121=log11^2=2log11=\boxed{2t}[/tex]
[tex]8)\\log363=log(121\cdot3)=log121+log3=log11^2+u=2log11+u=\boxed{2t+u}[/tex]