Bonjour,
A=7/9 - 5/2 : 4/3
A = 7/9 - 5/2 x 3/4
A = 7/9 - 15/8
A = (7 x 8) / (9 x 8) - (15 x 9) / (8 x 9)
A = 56/72 - 135/72
A = - 79/72
B= -3/5 + 4/3 x (1/-2 - -2/5)
B = - 3/5 + 4/3 x [(- 1 x 5) / (2 x 5) + (2 x 2) / (5 x 2)]
B = - 3/5 + 4/3 x (- 5/10 + 4/10)
B = - 3/5 + 4/3 x (- 1/10)
B = - 3/5 - 4/30
B = (- 3 x 6) / (5 x 6) - 4/30
B = - 18/30 - 4/30
B = - 22/30
B = (2 x - 11) / (2 x 15)
B = - 11/15
