SOLUTION: log9(3u + 14) - log9(5) = log9 2u Solve please. I know that the addition should be treated as multiplication. But, does that make it 42u? I also know that the logs are the same s

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: log9(3u + 14) - log9(5) = log9 2u Solve please. I know that the addition should be treated as multiplication. But, does that make it 42u? I also know that the logs are the same s      Log On


   

Question 857122: log9(3u + 14) - log9(5) = log9 2u
Solve please. I know that the addition should be treated as multiplication. But, does that make it 42u? I also know that the logs are the same so they cross out.
Found 2 solutions by jim_thompson5910, josmiceli:
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!






























I'll let you check the possible answer.

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+log%28+9%2C+3u+%2B+14+%29+-+log%28+9%2C+5+%29+=+log%28+9%2C+2u+%29+
The minus sign means you divide
This is the general rule:
+log%28a%29+-+log%28b%29+=+log%28+a%2Fb+%29+
-----------------------------
+log%28+9%2C+%28+3u+%2B+14+%29+%2F+5+%29+=+log%28+9%2C+2u+%29+
+%28+3u+%2B+14+%29+%2F+5+=+2u+
+3u+%2B+14+=+10u+
+7u+=+14+
+u+=+2+
-----------
check:
+log%28+9%2C+3u+%2B+14+%29+-+log%28+9%2C+5+%29+=+log%28+9%2C+2u+%29+
+log%28+9%2C+3%2A2+%2B+14+%29+-+log%28+9%2C+5+%29+=+log%28+9%2C+2%2A2+%29+
+log%28+9%2C+20+%29+-+log%28+9%2C+5+%29+=+log%28+9%2C+4+%29+
+log%28+9%2C+20%2F5+%29+=+log%28+9%2C+4+%29+
+log%28+9%2C+4+%29+=+log%28+9%2C+4+%29+
OK