Bonjour
A = (3x+2)² - (x-3)(x+7)
= 9x² +12x +4 - ( x² +7x -3x -21)
= 9x² +12x +4 - x² -7x +3x +21
= 8x² +8x +25
B = 2(x-1)² -3(2x-3)²
= 2(x² -2x+1) -3(4x² -12x +9)
= 2x² -4x +2 - (12x² -36x +27)
= 2x² -4x +2 -12x² +36x -27
= -10x² +32x -25
C = - (3x-1)² + (-x+1)(-4x +2)
= - ( 9x² -6x+1) + (4x² -2x - 4x +2)
= -9x² +6x -1 + 4x² -6x -2
= -5x² -3
D = (V3-1)² + (-x+1)(-4x+2)
= (3 -2V3+1) + (4x²-2x -4x +2)
= 4 - 2V3 + 4x² -2x -4x +2
= 4-2V3 +4x² -6x +2
E = (x-1)² + (x+3)(2x+1)
= x² -2x+1 + 2x² +x +6x +3
= 3x² +5x +4
A = (x-1)(2x+7) - (3x-2)(x-1)
= (x-1) ( 2x +7) - (3x-2)
= (x-1) (2x+7-3x+2)
= (x-1)( -x +9)
B = 4x² +1 +4 x
= x(4x +1 +4)
= x ( 4x+5)
C = (x+3)(3x-1) - (1-3x)(5x+2)
= (x+3)(3x-1) + (3x -1)(5x+2)
= (3x-1)( x+3) + (5x+2)
= (3x-1)(x+3+5x+2)
= (3x-1) (6x+8)
D = (2x-5)(x+2) - x² -4x -4
= je pense qu'il y a une erreur dans le dernier signe et que c'est +4 ( à vérifier)
E = (2x-5)(x-3) - (5-2x)(3x+4) +4x²-20x+25
= (2x-5)(x-3) + (2x-5)(3x+4) + (2x-5)²
= (2x-5) (x+3)+(3x+4) + (2x-5)
= (2x-5)(x+3+3x+4+2x-5)
= (2x-5) ( 6x +2)
F = (3x+1)² - (3x+1)(5x-2) -3x -1
= (3x+1)(3x+1)+(5x-2)-3x-1
= (3x+1)(3x+1+5x-2-3x-1)
= (3x+1) (5x -2)
