How do you solve log5^(2x) = 4?

1 Answer
Nov 4, 2015

The solution is x=2/log(5)

Explanation:

A property of lohgarithms states that

log(a^b)=blog(a)

In your case, a=5 and b=2x, so the equality becomes

log(5^{2x})=2xlog(5).

At this point, it's very easy to isolate the x, since log(5) is just a number, and we have

log(5^{2x}) = 4

iff

2xlog(5)=4

iff

x=4/(2log(5)) = 2/log(5)