Sagot :
A = (3-x)(2x+3)
A = 6x + 9 -2x²-3x
A = -2x² -3x + 9
B = 3x(4x-7)
B = 12x² - 21x
C = (10+x)(5+3x)-5x(3x+2)
C = (50+30x+5x+3x²) - (15x² +10x)
C = 3x² + 35x + 50 - 15x² -10x
C = -12x² +25x + 50
Bonsoir,
A= (3-x) (2x+3)
⇒double distributivité
A= 6x +9 -2x² -3x
A= -2x² + 3x + 9
B= 3x(4x-7)
⇒distributivité simple
B= 12x² - 21x
C= (10+x)(5+3x) - 5x (3x+2)
C= 50 + 30x + 5x +3x² - (15x² +10x)
C= 3x² + 35x + 50 - 15x² -10x
C= -12x² + 25x + 50
Bonne soirée.