Trl :
\(\frac{1}{9}.27^n=3^{n+2}\)
\(3^{-2}.\left(3^3\right)^n=3^{n+2}\)
\(3^{-2}.3^{3n}=3^{n+2}\)
\(\Rightarrow-2+3n=n+2\)
\(\Rightarrow3n=n+4\)
\(\Rightarrow2n=4\)\(\Rightarrow n=2\)
Hok tốt
Trl :
\(\frac{1}{9}3^4.3^n=3^7\)
\(3^{-2}.3^4.3^n=3^7\)
\(\Rightarrow-2+4+n=7\)
\(\Rightarrow2+n=7\)
\(\Rightarrow n=7-2\)
\(\Rightarrow n=5\)
Hok tốt !