Iread 40 pages of a book. this is equivalent to 2/3 of the whole book. how many pages does this book have?

There would be 60 pages in the book totally because you would set 40/x=2/3 and solve for x.

40/x=2/3

2x=120

x=60

your question is incomplete, write all the numbers in the sequence that it tells you.  

step-by-step explanation:

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)