Question 280461
2^(2x) -2^(x+1) -15 = 0 



(2^x)^2 -2*2^x -15 = 0 


z^2-2z-15=0


(z-5)(z+3)=0


z-5=0 or z+3=0


z=5  or z=-3


2^x=5  or 2^x=-3


2^x=-3 ----> no solution


2^x=5 ----> *[Tex \LARGE x=\log_{2}(5)]


Answer: *[Tex \LARGE x=\log_{2}(5)]