Question

-9+3^-2x-83^-x=0 sos sossososososos

Answer 1

$-9+3^{-2x}-8cdot3^{-x}=0,,y=3^{-x},,y^2-8x-9=0,,(y+1)(y-9)=0,$
$y=9,,3^{-x}=3^2,,-x=2,,x=-2$