This questions comes from the free GMAT online practice test.

2^{x}-2^{x-2}=3 (2^{13})

Solve for X

Answer: X = 15

I have searched the internet for over an hour trying to find an example for this particular type of equation, and I looked at all the exponent questions in the Official GMAT guide and the Official Quantitative Guide, and there are no problems like this in there.

Please explain how this is solved, in the simplest way possible, because the GMAT only allows 1-2 minutes to solve each problem. In particular, even if I solved the right side the long way, I still don't know what to do with the ^{x-2}. I am so confused. Please help!

Elizabeth G.

Can you explain each line with words, though. Because I can't really understand this04/02/19