Explications étape par étape:

N1 = 3 ( x + 1 )

N2 = ( x + 1 ) ( x + 12 )

N3 = ( x + 1) ( 4x + 1 )

N4 = 4 ( x + 1 ) au carré

N5 = ( x + 1 ) ( 8x + 1 )

N6 = 3 ( 3x - 4) ( x + 1 )

N7 =( x + 1 ) ( x + 3 )

N8 = 4 ( x + 1 ) ( x + 5 )

N9 = ( x + 1 ) ( 8x + 15 )

N10 = ( x + 1 ) ( 3x + 19 )

N11 = ( x + 1 ) ( 2x + 17 )

N12 = ( x + 1 ) ( x + 2 )

N13 = ( 7x - 19 ) ( x + 1 )

N14 = - ( 7x - 30 ) ( x + 2 )

N15 = 2x ( x + 1 )

N16 = ( x + 1 ) ( x + 4 )

N17 = ( x + 1 ) x puissance 4 - x - 1

N18 = ( 3x - 2 ) ( x + 1 )

N19 = ( x + 1 ) ( 4x + 5 )

N20 = ( x - 1 ) ( x + 1 ) ( x carré + 1 )