\(=\left(2x+1+x-1\right)\left(2x+1-x+1\right)=3x\left(x+2\right)\)
(2x + 1)2 - (x - 1)2
= (2x + 1 + x - 1).(2x + 1 - x + 1)
= 3x.(x + 2)
Ủng hộ mk nha ^_-
(2x+1)2 - (x-1)2
=4x2 + 4x + 1 - ( x2 -2x + 1 )
= 4x2 + 4x + 1 - x2 + 2x -1
= 3x2 + 6x
Nhớ k giùm mk nha