Hi,

Getting ready to go back to college and will be taking a precalculus test for placement. I was given a practice exam to study from that comes with the answers, but it doesn't really do a great job of explaining how to get the answers.

here is the problem:

8^x =

2^x-1

the answer is: 2^2x+1

I have no idea how to get that answer. Thank you in advance for your help!