Thread: Solving Logarithmic/Exponential Equations

Hey everyone, I've tried these log problems, but to no avail.

25^(x-1) = 125^4x
I tried this:

(5^2)^x-1 = (5^3)^4x
5^(2x-2) = 5^12x
2x-2 = 12x

Here, I was confused. No substitution would make it work. (The instant math solver says -1/5)
Am I going at this the wrong way?

Thank you for the help!

Originally Posted by radh

Hey everyone, I've tried these log problems, but to no avail.

25^x-1 = 125^4x
I tried this:

(5^2)^x-1 = (5^3)^4x
5^2x-2 = 5^12x
2x-2 = 12x

Here, I was confused. No substitution would make it work. (The instant math solver says -1/5)
Am I going at this the wrong way?

Also, for clarification (in two examples), here's another problem:
36^x-9 = 6^2x
I tried this:

(6^2)^x-9 = (6)^2x
6^2x-18 = 6^2x
2x-18 = 2x

Which once again comes up with an impossible substitution.

Thank you for the help!

Is it or , or something else entirely?

It's 25^(x-1) and 36^(x-9). I apologize for the confusion.

You are correct up to , so