(2x - 15 ) mũ 3 = ( 2 mũ 2 . 3 mũ 3 - 2 mũ 3 . 3 mũ 2 ) : ( - 36 )

`(2x-15)^3 = (2^2 .3^3 -2^3 .3^2 ) :(-36)`

`(2x-15)^3 = (4 . 27 - 8 . 9) :(-36)`

`(2x-15)^3 = (108 -  72) :(-36)`

`(2x-15)^3 = 36 : (-36)`

`(2x-15)^3 = -1`

`(2x-15)^3 = (-1)^3`

`=> 2x-15 =-1`

`2x = -1 +15`

`2x = 14`

`x = 14:2`

`x = 7`

`text{Vậy,}` `x=7`

$#hongnhung27092k10$