\(25^{2n}:5^n=125\)
\(\left(5^2\right)^{2n}:5^n=5^3\)
\(5^{2.2n}:5^n=5^3\)
\(5^{4n-n}=5^3\)
\(5^{3n}=5^3\)
\(3n=3\)
\(n=3:3\)
\(n=1\)
\(\Leftrightarrow5^{4n}:5^n=125\)
=>5^3n=5^3
=>3n=3
=>n=1
\(25^{2n}:5^n=125\\ \left(5^2\right)^{2n}:5^n=125\\ 5^{4n}:5^n=5^3\\ 5^{4n-n}=5^3\\ \Rightarrow3n=3\\ \Leftrightarrow n=1\)
\(25^{2n}:5^n=125\)
\(\Rightarrow\left(5^2\right)^{2n}:5^n=5^3\)
\(\Rightarrow5^{2\cdot2n}:5^n=5^3\)
\(\Rightarrow5^{4n}:5^n=5^3\)
\(\Rightarrow5^{4n-n}=5^3\)
\(\Rightarrow5^{3n}=5^3\)
\(\Rightarrow3n=3\)
\(\Rightarrow n=\dfrac{3}{3}\)
\(\Rightarrow n=1\)