SOLUTION: solve log(x+20)-log(x+2)=logx

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: solve log(x+20)-log(x+2)=logx      Log On


   

Question 455693: solve log(x+20)-log(x+2)=logx
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
log%28%28%28x%2B20%29%2F%28x%2B2%29%29%29+=+logx
==> %28x%2B20%29%2F%28x%2B2%29+=+x
==> x%2B+20+=+x%28x%2B2%29
==> x%2B20+=+x%5E2+%2B+2x
==> 0+=+x%5E2+%2B+x++-+20
==> 0 = (x +5)(x - 4) ==> x = -5, 4.
-5 does not satisfy the original equation. Hence the final answer is x = 4.