SOLUTION: Hi. I need assistance with this LOG problem. I got this far: log((w+8)/(w-5)) Thank you! Solve log(w+8)-log(w-5)=1 w=__________ Hint: use the laws of logs to combine into a si

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: Hi. I need assistance with this LOG problem. I got this far: log((w+8)/(w-5)) Thank you! Solve log(w+8)-log(w-5)=1 w=__________ Hint: use the laws of logs to combine into a si      Log On


   



Question 712366: Hi. I need assistance with this LOG problem. I got this far: log((w+8)/(w-5)) Thank you!
Solve log(w+8)-log(w-5)=1
w=__________
Hint: use the laws of logs to combine into a single log.

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
You have to know what the base is,
and when it's not stated, you can
usually assume it is +10+
The trick here is to use
+log%28+10+%29+=+1+
+log%28+w%2B8+%29+-+log%28+w-5+%29+=+log%28+10+%29+
+log%28+%28+w%2B8+%29%2F%28+w-5+%29+%29+=+log%28+10+%29+
Now you can say
+%28+w%2B8+%29+%2F+%28+w-5+%29+=+10+
+w+%2B+8+=+10%2A%28+w+-+5+%29+
+w+%2B+8+=+10w+-+50+
+9w+=+58+
+w+=+6.4444+
check:
+log%28+6.4444%2B8+%29+-+log%28+6.4444-5+%29+=+1+
+log%28+14.4444+%29+-+log%28+1.4444+%29+=+1+
+1.1596995+-+.159687+=+1.0000125+
I think the error is due
to rounding off