5\(^x\) . (5\(^3\))\(^2\) = 625 5\(^x\) . 5\(^6\) = 5\(^4\) 5\(^x\) = 5\(^4\) : 5\(^6\) 5\(^x\) = 5\(^{-2}\) => x = -2
\(5^x.\left(5^3\right)^2=625\)
\(5^x.5^6=5^4\)
\(5^x=5^4:5^6\)
\(5^{x=5^{-2}}\)
\(\Rightarrow x=\left(-2\right)\)
Vậy \(x=\left(-2\right)\)