How do you solve 7^(x-2)=5^x?

1 Answer
Jul 1, 2016

x=2 /(1 - log_7 5)

Explanation:

7^(x-2)=5^x

log 7^(x-2)=log 5^x

(x-2) log 7=x log 5

x(log 7 - log 5)=2 log 7

x=(2 log 7)/(log 7 - log 5)

specifically choosing base 7 for the log

x=2 /(1 - log_7 5)