Réponse :
Bonjour
Explications étape par étape
A = ( x+5)( x – 7) – (3 x+1) (x+2)
A = x² -7x +5x -35 - (3x² +6x +x +2)
A = x² -2x -35 - ( 3x² +7x +2)
A = x² -2x -35 -3x² -7x -2
A = -2x² -9x -37
B = (2 x+3) (3 x – 1) + (x+1) (x+4)
B = 6x² -2x +9x -3 + x² +4x +x +4
B = 6x² +12x +1
C = (5 x−1) 2 + (3 x+7) (3 x−7)
C = +10x -2 + 9x² -21x +21x -49
C = +9x² +10x -51
D = ( x−7)2 − (4 x−7)2 =
D = 2x -14 - (8x -14)
D = 2x -14 -8x +14
D = -6x
