Question

Tìm x, biết 9^2x-1=27^x

Answer 1

 

<=> (3²)^2x-1 = (3³)^x

<=> 3^4x-2 = 3^3x

<=> 4x - 2 = 3x

<=> 4x -3x -2 = 0

<=> x - 2 = 0 ; <=>x = 2

Answer 2

3^4x-2 = 3^3x

4x-2=3x

x=2

Answer 3

   3^2x-1= 27^x

x =  2x-2 =3x

x = 2