\(5^{x+1}+5^{x+2}=6.125\)
\(\Rightarrow5^{x+1}+5^{x+1}.5=6.125\)
\(\Rightarrow5^{x+1}\left(1+5\right)=6.125\)
\(\Rightarrow5^{x+1}.6=6.125\)
\(\Rightarrow5^{x+1}=125\)
\(\Rightarrow5^{x+1}=5^3\)
\(\Rightarrow x+1=3\)
\(\Rightarrow x=2\)
Vậy x = 2