Ta co : \(3^x+3^{x+2}=2430\)
\(3^x.1+3^x.3^2=2430\)
\(3^x\left(1+3^2\right)=2430\)
\(3^x.10=2430\)
\(3^x=2430:10\)
\(3^x=243\)
\(\Rightarrow3^x=3^5\)
Vay x=5
**** nhe
\(3^x+3^{x+2}=2430\)
=> \(3^x.\left(1+3^2\right)=2430\)
=>\(3^x.10=2430\)
=>\(3^x=243\)
=>\(3^x=3^5\)
Vậy \(x=5\).