A=2x(3x-7)
B=(5x+1)(2x-3)
C=(7x-3)² -(7x-3) (2x-5)
x=lettre
A = 6x² - 14x
B = 10x² - 15x + 2x - 3
= 10x² - 13x - 3
C = (7x - 3) [(7x - 3) - (2x - 5)]
= (7x - 3) (5x + 2)
= 35x² + 14x - 15x - 6
= 35x² - x - 6
Bonsoir
A = 6x²-14x
B = 10x²-15x+2x-3 = 10x²-13x-3
C = 49x²-42x+9 - (14x²-35x-6x+15)
= 49x² -42x +9 -14x² +35x +6x -15
= 35x² -x -6
