Question

\(3^x+3^{x+1}+3^{x+2}=117\)

Answer 1

\(3^x+3^{x+1}+3^{x+2}=117\)

\(\Rightarrow3^x+3^x.3+3^x.3^2=117\)

\(\Rightarrow3^x.\left(1+3+3^2\right)=117\)

\(\Rightarrow3^x.13=117\)

\(\Rightarrow3^x=9\)

\(\Rightarrow3^x=3^2\)

\(\Rightarrow x=2\)

Vậy \(x=2\)

Answer 2

\(\Rightarrow3^x\left(1+3+3^2\right)=117\)

\(\Rightarrow3^x.13=117\)

\(\Rightarrow3^x=9\)

=>x = 2

Vây x = 2