Utiliza [] para representar la base.
Conocido:
Logaritmo[1/27]
=log[(3)^(-3)] 1/7
=-1/3 log[3](7^(-1))
=(-1/3)*(-1)log[3]7
= 1/3 log3 7
=a
Entonces log[3]7=3a.
Logaritmo[1/3]
=(-1)log[3]{5^(-1)}
=(-1) * (-1)log[3]5
=log[3]5
=b
log[81]175
=log[3^4](5*5*7)
=1/4(log 5+log 5+log 7)
= 1/2 log5+1/ 4 log7
=b/2+3a/4