I need to use the exponential function methodology for full marks.

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)

explanation:

the loan estimate encourages consumers to shop. since it is the lenders who are required to issue a standardized loan estimate in a specific time frame, this way consumers are provided an opportunity to compare lenders and their products. otherwise consumer wouldn't know the benefits offered by other lenders.  

if a loan originator does not provide a loan estimate within 3 business days of receiving a completed loan application, that lender is in violation. lenders are required to issue a loan estimate within 3 days of applying for a loan or within 7 days prior to closing. having a loan estimate has following information.

not having loan estimate won't give you an idea of money to be borrowed.

you get to know your interest rates.

you also get to know if your interest rate can or may vary.

not having a good faith estimate can keep you unaware of aforementioned points.

d will be the best answer