Question

Tìm số nguyên n khi

27^n : 3^n = 9

Answer 1

\(27^n:3^n=9\)

Khi n = 1

Answer 2

<=> \(\frac{3^{3n}}{3^n}=9\)<=> \(3^{2n}=3^2\)<=>n=1

Answer 3

\(27^n\div3^n=9\)

\(\Rightarrow3^{3n}\div3^n=9\)

\(\Rightarrow3^{3n-n}=9\)

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

\(\Rightarrow2n=2\)

\(\Leftrightarrow n=1\)

Vậy muốn 27^n : 3^n = 9 thì n=1

Answer 4

27^n:3^n=9

(3^3)^n:3^n=3^2

3^3n:3^n=3^2

3^3n-n=3^2

3^2n=3^2

=> 2n=2

n=2:2

n=1

Vậy n=1

Answer 5

\(27^n:3^n=9\)

\(\Rightarrow\left(27:3\right)^n=9\)

\(\Rightarrow9^n=9\)

\(\Rightarrow9^n=9^1\)

\(\Rightarrow n=1\)

Vậy n = 1

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