logb16 - log9b5 + 1

logb16 - 5·log9b + 1

on the middle term we use 

logb16 -  + 1

For the 1 on the right we use logbb = 1

logb16 -  + logbb

Swap the 2nd and 3rd terms:

logb16 + logbb -  

logb16b - 

To keep it from getting too messy. let A = logb9

logb16b - 

Get the LCD and combine terms:







Write 5 as logbb5









Finally replace A by logb9



That's a mess because you had mixed bases 
in the beginning.

Edwin