SOLUTION: write the following expression as a single logarithm: log x/ log 7- log y. I got the answer log x/ 7y. but I searched the internet and they said that the answer was log 7x/ y. so w

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: write the following expression as a single logarithm: log x/ log 7- log y. I got the answer log x/ 7y. but I searched the internet and they said that the answer was log 7x/ y. so w      Log On


   

Question 763213: write the following expression as a single logarithm: log x/ log 7- log y. I got the answer log x/ 7y. but I searched the internet and they said that the answer was log 7x/ y. so which is the right answer and how did you get that?
thanks,
Nick
Answer by josgarithmetic(39838) About Me  (Show Source):
You can put this solution on YOUR website!
Recheck your book to review these rules about logarithms:

highlight%28log%28a%2Ab%29=log%28%28a%29%29%2Blog%28%28b%29%29%29

highlight%28log%28a%2Fb%29=log%28%28a%29%29-log%28%28b%29%29%29

TRUST those rules. Your given expression, log%28x%29%2Flog%287%29-log%28y%29 which seems to be according to how you showed it, the ratio of logarithms MINUS another logarithm. I believe you cannot condense that into a single logarithm.

You may try this way:
but this does not help.

Again, as said, you showed ratio of two logs minus another log. No rule for that. Are you SURE that your original expression was as you wrote?