Question

[x - 1] x [5^x - 125] = 9 - 3^11 : 3 ^9

Answer 1

\(\Rightarrow\left(x-1\right)\left(5^x-125\right)=9-3^2=0\\ \Rightarrow\left[{}\begin{matrix}x=1\\5^x=125=5^3\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=1\\x=3\end{matrix}\right.\)

Answer 2

(x - 1 ) . ( 5^x - 125 ) = 9 - 3¹¹ : 3⁹

(x - 1 ) . (5^x - 125) = 9 - 3^11-9

(x - 1) . (5^x - 125) = 9 - 3² 

(x -1) . (5^x - 125) = 9 - 9 = 0

=> x = 1 hoặc 2

Answer 3

\(\Leftrightarrow\left[{}\begin{matrix}x-1=0\\5^x=125\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=1\\x=3\end{matrix}\right.\)