Question

Tìm n thuộc N* biết :

3^2 x 3^n = 3^n 

Answer 1

Ta có:

\(3^2\times3^n=3^n\)

\(\Rightarrow3^{n+2}=3^n\)

\(\Rightarrow n+2=n\)(Vô lí)

Vậy \(n\in\varnothing\)

T**k mik nhé!

Answer 2

\(3^2.3^n=3^n\)

\(\Leftrightarrow9.3^n=3^n\)

\(\Leftrightarrow9=3^n\div3^n\)

\(\Leftrightarrow9=1\left(voli\right)\)

\(\Rightarrow n\in\left\{\varnothing\right\}\)

Answer 3

\(3^2.3^n=3^n\)

\(\Leftrightarrow9.3^n=3^n\)

\(\Leftrightarrow9=3^n\div3^n\)

\(\Leftrightarrow9=1\) (vô lí )

Vậy \(x\in\left\{\varnothing\right\}\)