Question

Ai giúp mk câu này vs

\(3^{x-1}:3=\frac{1}{243}\)

 

Answer 1

\(\Rightarrow3^{x-1}=\frac{1}{243}x3\)

\(\Rightarrow3^{x-1}=\frac{1}{81}\)

Ko có x thỏa mãn

Answer 2

\(3^{x-1}:3=\frac{1}{243}\)

\(3^{x-2}=3^{-5}\)

\(\Rightarrow x-2=-5\)

\(x=-3\)

Vậy x= -3

Answer 3

3^x-1 : 3 = \(\frac{1}{243}\)

=> 3^x-1 = \(\frac{1}{81}\)

mà 81 = 9²

=> 3^x-1 = \(\frac{1}{\left(9^2\right)}\)

=> x = ..........

rắc rối chắc sai quá !! 564575475675687857556686586444456

Answer 4

\(3^{x-1}:3=\frac{1}{243}\)

\(\Leftrightarrow3^{x-1}:3=\frac{1}{3^5}\)

\(\Leftrightarrow3^{x-1}:3=3^{-5}\)

\(\Leftrightarrow3^{x-1}=3^{-5}.3=3^{-4}\)

\(\Leftrightarrow x-1=-4\)

\(\Leftrightarrow x=-4+1=-3\)   

      Vậy \(x=-3\)