Question 563705
1. {{{log (b,15)=log (b,(3*5))=log (b,3)+log (b,5)=1.5+2.2=3.7}}}
Use the properties of logarithm  {{{log (b,(a*c))=log (b,a)+log (b,c)}}}
2.{{{ log (b,0.6)=log (b,(3/5))=log (b,3)-log (b,5)=1.5-2.2=-0.7}}}
Use the properties of logarithm  {{{log (b,(a/c))=log (b,a)-log (b,c)}}}
3. {{{log (b,125)=log (b,(5^3))=3*log (b,5)=3*2.2=6.6}}}
Use the properties of logarithm  {{{log (b,(a^n))=n*log (b,a)}}}
4. {{{log (b, (root(3, 3))^7)=log (b, ((3)^(1/3))^7)=log (b, (3)^(7/3))=(7/3)*log (b, 3)=(7/3)*1.5=3.5}}}