Question

Daca 4^x+4^-x=23, atunci nr 2^x+2^-x apartine carei multimi? URGENT

Answer 1

ai rezolvarea în imagine

Answer 2

$4^{x}+ 4^{-x}=23 \\ (2^x+ 2^{-2})^2=4^x+2*2^x* 2^{-x}+ 4^{-x}=23+2 =25 \\ (2^x+ 2^{-x)}= \sqrt{25} \\ 2^x+ 2^{-x}=5;2^x+ 2^{-x}=-5$