48 / 6 = x
in this case, x will equal the amount of money in each card!
x therefore will be 8.
trent had $8 in each birthday card.
you didn't post any answer choices, so its not 100% clear what your teacher is looking for
however, log(15/7) is equivalent to log(15) - log(7)
i'm using the rule log(x/y) = log(x) - log(y)