SOLUTION: How would you solve this : log (4+x) - log (x-4)= log 3 I don't even know where to begin , I've never seen a logarithmic equation set up equal to log 3 .

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: How would you solve this : log (4+x) - log (x-4)= log 3 I don't even know where to begin , I've never seen a logarithmic equation set up equal to log 3 .      Log On


   

Question 473408: How would you solve this :
log (4+x) - log (x-4)= log 3
I don't even know where to begin , I've never seen a logarithmic equation set up equal to log 3 .
Answer by ccs2011(207) About Me  (Show Source):
You can put this solution on YOUR website!
Use log property: log+a+-+log+b+=+log+%28a%2Fb%29 to combine left side into a single log.
log+%28%284%2Bx%29%2F%28x-4%29%29+=+log+3
Rewrite equation in exponential form, Or notice that if log(a)=log(b) then a=b
%284%2Bx%29%2F%28x-4%29+=+3
Multiply by (x-4) on both sides
4%2Bx+=+3%28x-4%29
Distribute
4%2Bx+=+3x+-+12
Subtract 3x on both sides
4+-+2x+=+-12
Subtract 4 on both sides
-2x+=+-16
Divide by -2 on both sides
x+=+8