Question

Tìm x biết 3^x+3^x-5 = 2196

Answer 1

`3^x + 3^(x-5) =2196`

`3^x *1 + 3^x * 1/(3^5) =2196`

`3^x ( 1 + 1/(3^5) ) = 2196`

`3^x * 244/243 = 2196`

`3^x =2178`

`3^x =3^7`

`=> x=7`