Which expression is equivalent to log8 4a (b-4/c4) ?

The answer:

the main rules of the use of logarithm are

loga[a] = 1

loga[AxB] = loga[A] + loga[B] for all value positive of A and B

loga[A/B] = loga[A] - loga[B] for all value positive of A and B

in our case, log8 4a (b-4/c4)

so it is equivalent to log8 4a + log8 (b-4/c4)

and since loga[A/B] = loga[A] l - oga[B], log8 (b-4/c4) = log8 (b-4) - log8 (c4)

the possible expression:

log8 4a (b-4/c4) = log8 4a + log8 (b-4) - log8 (c4)