Calcul: À= (2/6-6/9)X4-3X7/12 B= 16(x-1)*-49 *=au carré Merci :)

A = (2/6 - 6/9) X 4 - 3 X 7/12
A = (2 x 3 / 6 x 3 - 6 x 2 / 9 x 2) x 4 - 21/12
A = (6/18 - 12/18) x 4 - 21/12
A = - 6/18 x 4 - 21/12
A = - 24/18 - 21/12
A = - 24 x 2 / 18 x 2 - 21 x 3 / 12 x 3
A = - 48/36 - 63/36
A = - 111/36
A = 3 x - 37 / 3 x 12
A = - 37/12

B = 16 (x - 1)² - 49 
B = 16 (x² - 2x + 1) - 49
B = 16x² - 32x + 16 - 49
B = 16x² - 32x - 33