Question

tìm x biết 5^x . 125^x =625

Answer 1

\(5^x.125^x=625\)

\(\Leftrightarrow5^x.\left(5^3\right)^x=5^4\)

\(\Leftrightarrow5^x.5^{3.x}=5^4\)

\(\Leftrightarrow5^{x+3x}=5^4\)

\(\Leftrightarrow x+3x=4\)

\(\Leftrightarrow4x=4\)

\(\Leftrightarrow x=1\)

Vậy x=1

Answer 2

5^x . 125^x = 625

<=> (5 . 125)^x = 625

<=> 625^x = 625

<=> x = 625 : 625

<=> x = 1

Answer 3

\(5^x.125^x=625\)

\(\Leftrightarrow\left(5.125\right)^x=625\)

\(\Leftrightarrow625^x=625\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=1\end{matrix}\right.\)

Vậy ..