Question

[tex]9 ^{-x} =27


sase rezolve ecuatia

Answer 1

$9^{-x} = 27$ ⇔$( 3^{2} )^{(-x)} = 3^{3}$⇔$3^{-2x} = 3^{3}$
Pe baza injectivitatii functiei exponentiale deducem ca:
$-2x=3$⇔$2x=-3$⇒$x= -\frac{3}{2}$