Question

\(\frac{1}{9}\).27ⁿ = 3^{n +2}

\(\frac{1}{9}\).3⁴ . 3ⁿ = 3⁷ 

\(\frac{1}{2}\). 4ⁿ + 4.4ⁿ = 9 . 2^{n + 1}

Answer 1

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

Answer 2

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 !