How do you do log subscript 7, multiplied by one over three- forty- three

So I assume you have this....

log₇ (1/343)

First...look at something

Note......(7)^-1 = (1/7¹) = (1/7)

And    (7)^-2= (1/7²)  = (1/49)

And    (1/7)^-3  = (1/7³) = (1/343)

So .... log₇ (1/343) is just asking us..."What exponent (power) do we need to put on 7 to get (1/343) ??"     And the answer is....    -3   

(Don't get confused....we're not "multiplying" anything.....!!)

Hope that helps.....