\(a,2^n=8\)
\(2^n=2^3\)
Vậy \(n=3\)
__________
\(b,7^n=49\)
\(7^n=7^2\)
Vậy \(n=2\)
__________
\(c,4^n=64\)
\(4^n=4^3\)
Vậy \(n=3\)
__________
\(d,5^n=625\)
\(5^n=5^4\)
Vậy \(n=4\)
\(a,2^n=8\)
\(2^n=2^3\)
\(\Rightarrow n=3\)
\(b,7^n=49\)
\(7^n=7^2\)
\(\Rightarrow n=2\)
\(c,4^n=64\)
\(4^n=4^3\)
\(\Rightarrow n=3\)
\(d,5^n=625\)
\(5^n=5^4\)
\(\Rightarrow n=4\)