(2x-1)3-(2x-1)=(2x-1) [( 2x-1)2 -1 ]
= 2x (2x -1 ) ( 2x-2)
(2x - 1)3 - (2x - 1)
= (2x - 1)[(2x - 1)2 - 1]
= (2x - 1)(4x2 - 4x + 1 - 1)
= (2x - 1)(4x2 - 4x)
Trả lời:
( 2x - 1 )3 - ( 2x - 1 )
= ( 2x - 1 ) [ ( 2x - 1 )2 - 1 ]
= ( 2x - 1 ) ( 2x - 1 - 1 ) ( 2x - 1 + 1 )
= 2x ( 2x - 1 ) ( 2x - 2 )