Question

Tìm n €N , biết

a,2019 ^n =1

b, 2^n+1 =16

c,2^n=32

d,4^n-1=64

e,5^2n-1=125

Giải giúp mik nhanh nhé , chiều mik phải nộp rùi

Answer 1

a, \(2019^n=1\)

Mà \(2019>1\)

\(\Rightarrow n=0\)

Vậy n = 0

b, \(2^{n+1}=16\\ \Rightarrow n+1=4\\ \Rightarrow n=3\)

Vậy n = 3

c, \(2^n=32\\ \Rightarrow n=5\)

Vậy n = 5

d, \(4^{n-1}=64\\ \Rightarrow n-1=3\\ \Rightarrow n=4\)

Vậy n = 4

e, \(5^{2n-1}=125\\ \Rightarrow2n-1=3\\ \Rightarrow2n=4\\ \Rightarrow n=2\)

Vậy n = 2

Answer 2

a, \(2019^n=1\)

\(\Rightarrow n=0\)

\(b,2^{n+1}=16\)

\(\Rightarrow2^{n+1}=2^4\)

\(\Rightarrow n+1=4\)

\(\Rightarrow n=3\)

c, \(2^n=32\)

\(2^n=2^5\)

\(\Rightarrow n=5\)

d, \(4^{n-1}=64\)

\(\Rightarrow4^{n-1}=4^3\)

\(\Rightarrow n-1=3\)

\(\Rightarrow n=4\)

e, \(5^{2n-1}=125\)

\(\Rightarrow5^{2n-1}=5^3\)

\(\Rightarrow2n-1=3\)

\(\Rightarrow2n=4\)

\(\Rightarrow n=2\)

Chúc bạn học tốt!