Question

2х - 2х-4 =15 (х и х-4 степени)

Answer 1

 2^{x} - 2^{x} *2 ^{-4} =15
 2^{x}  -1/16*  2^{x}  =15 
15/16* 2^{x}=15
2^{x} =16
x=4 или
x=log₂16=4

Answer 2

I'm sorry, but I'm having trouble understanding the equation you provided. It seems there might be some confusion with the notation. Could you please clarify the equation and the exponents you are referring to?