Répondre :
Bonsoir
A = (3x + 1)(7x - 1) + 29x² + 1 + 3(7x - 4)
A = (21x² - 3x + 7x - 1) + 29x² + 1 + (21x - 12)
A = 21x² - 3x + 7x - 1 + 29x² + 1 + 21x - 12
A = 50x² + 25x - 12
B = (5x + 4)² + (5x + 4)(5x - 7)
B = (25x² + 40x + 16) + (25x² - 35x + 20x - 28)
B = 25x² + 40x + 16 + 25x² - 35x + 20x - 28
B = 50 x² + 25x - 12
Donc A = B = 50 x² + 25x - 12
A = (3x + 1)(7x - 1) + 29x² + 1 + 3(7x - 4)
A = (21x² - 3x + 7x - 1) + 29x² + 1 + (21x - 12)
A = 21x² - 3x + 7x - 1 + 29x² + 1 + 21x - 12
A = 50x² + 25x - 12
B = (5x + 4)² + (5x + 4)(5x - 7)
B = (25x² + 40x + 16) + (25x² - 35x + 20x - 28)
B = 25x² + 40x + 16 + 25x² - 35x + 20x - 28
B = 50 x² + 25x - 12
Donc A = B = 50 x² + 25x - 12