Răspuns :
[(4x+1)-(2x+3)][(4x+1)+(2x+3)]=
=(4x+1-2x-3)(4x+1+2x+3)=
=(2x-2)(6x+4)=
=2(x-1)(3x+2)
=(4x+1-2x-3)(4x+1+2x+3)=
=(2x-2)(6x+4)=
=2(x-1)(3x+2)
(4x + 1)² - (2x + 3)² = 16x² + 8x + 1 - 4x² - 12x - 9 =
12x² -4x - 8 = 4(3x² - x - 2) =
= 4(3x² - 3x + 2x - 2) =
= 4(3x(x - 1) + 2(x - 1)) =
= 4(x - 1)(3x + 2)
12x² -4x - 8 = 4(3x² - x - 2) =
= 4(3x² - 3x + 2x - 2) =
= 4(3x(x - 1) + 2(x - 1)) =
= 4(x - 1)(3x + 2)