Question

(3^x+2 - 3^x+1) + 3^x = 139

Answer 1

\(3^x.9-3^x.3+3^x=139\\ 3^x\left(9-3+1\right)=139\\ 3^x.7=139\\ 3^x=\dfrac{139}{7}\)

:0

Answer 2

`(3^(x+2) - 3^(x+1) ) +3^x = 139`

`<=> 3^x * 3^2 - 3^x * 3 +3^x =139`

`<=> 3^x * (3^2 -3 +1) =139`

`<=> 3^x * 7 = 139`

`<=> 3^x = 139/7 `

`=> x ∈∅`