Question

How do you evaluate `log_(1/13) (1/169)`?

Answer 1

`2`

Explanation:

Spotting that `169=13^2` so you need `log_(1/13)(1/13^2)`.
Since `log_a(x^2)=2log_a(x)` and `log_a(a)=1` you get
`log_(1/13)((1/13)^2)=2log_(1/13)(1/13)=2 xx 1 = 2`.