[tex]3^x+\dfrac{1}{3^x}=\dfrac{10}{3} [/tex]
Notam [tex]3^x=a>0[/tex] si aducem la acelasi numitor:
[tex]a+\dfrac1a=\dfrac{10}{3}\Rightarrow 3a^2-10a+3=0\Rightarrow a_{1;2}=\dfrac{10\pm8}{6}[/tex]
[tex]a_1=3;\ \ \ a_2=\dfrac13=3^{-1}[/tex]
[tex]3^x=3\Rightarrow x=1;\ \ \ 3^x=3^{-1}\Rightarrow x=-1[/tex]
