For this case we have that by properties of logarithm that:
[tex]log_ {b} (a) = c[/tex] is equivalent to the following expression:
[tex]b ^ c = a[/tex]
We have the following expression:
[tex]log_ {7} () = - 3[/tex]
Then, according to the property we have:
[tex]7 ^ {- 3} =[/tex]
ANswer:
[tex]7 ^ {- 3} =[/tex]
Option A
