\(27^{n+1}\cdot9=3^{17}\)
\(3^{3^{n+1}}\cdot3^2=3^{17}\)
\(3^{3n+3+2}=3^{17}\)
\(3n+3+2=17\)
\(3n=12\)
\(n=4\)
27ⁿ⁺¹ . 9 = 3¹⁷
(3³)ⁿ⁺¹ . 3² = 3¹⁷
3³ⁿ⁺³ = 3¹⁷ : 3²
3³ⁿ⁺³ = 3¹⁵
3n + 3 = 15
3n = 15 - 3
3n = 12
n = 12 : 3
n = 4
\(27^{n+1}\times9=3^{17}\\ \Leftrightarrow27.\left(3^3\right)^n\times3^2=3^{17}\\ \Leftrightarrow3^3.3^{3n}=3^{17}:3^2\\ 3^3.3^n=3^{15}\\ \Leftrightarrow3^{3n}=3^{15}:3^3\\ \Leftrightarrow3^{3n}=3^{12}\\ \Rightarrow3n=12\\ \Leftrightarrow n=4\)
Vậy n = 4