HELP!!! Give an example of a logarithm that you would need to use the change of base formula to evaluate. Why do you need to use the change of base formula?

Question

campbell_st · Answer

what about logs with different bases.... 

use change of base to change the left hand side to base 5..

$$\log _{3} 2x = \log _{5} x + 7$$

anonymous · Answer

confused still...

campbell_st · Answer

ok... so you can't solve  for x until you get the log bases the same.... you need change of base on the left hand side

$$\frac{\log _{5}(x)}{\log _{5}(2)} = \log _{5}(x + 7)$$

anonymous · Answer

is there a more simple example? like could you say..hold on

anonymous · Answer

$$\log_{5} 3$$

anonymous · Answer

=

anonymous · Answer

log3/log5

anonymous · Answer

@campbell_st ?

campbell_st · Answer

what about $$\log _{3} 2x = \log _{7}(4)$$

anonymous · Answer

does it have to have a variable?