Bonjour
A=(-7x -10) (-3x +5)
A = 21x² - 35x + 30x - 50
A = 21x² - 5x - 50
B=(3x-6)(3x+6)
B = 9x² - 36
C=(10x-3)²
C = 100x² - 60x + 9
D= (6x+9)²
D = 36x² + 108x + 81
E=(9x+2)²-(8x+5)(8x-5)
E = 81x² + 36x + 4 - (64x² - 25)
E = 81x² + 36x + 4 - 64x² + 25
E = 81x² - 64x² - 36x + 4 + 25
E = 17x² - 36x + 29
F=(7x+7) (-7x+5)-(7x-9)²
F = - 49x² + 35x - 49x + 35 - (49x² - 126x + 91)
F = - 49x² + 35x - 49x + 35 - 49x² + 126x - 91
F = - 49x² - 49x² + 35x + 126x - 49x + 35 - 91
F = - 98x² + 112x - 56.
