Question

tìm x

1/3^x-1=1/243

 

Answer 1

\(\frac{1}{3^{x-1}}=\frac{1}{243}=\frac{1}{3^5}\)

\(\Rightarrow x-1=5\)

\(x=6\)

Answer 2

1/3^x-1=1/243

suy ra 1^x-1/3^x-1=1/243

1/3^x-1=1/243

1/3^x-1=1/3^5

suy ra x-1=5

x=5+1=6.

vậy x thuộc {6}.

chúc bạn học giỏi nhe.