Calculer et donner les résultats sous forme de fraction irréductibles. Svppp j’ai besoin de votre aide !

Bonjour

A = -5/12 - 7/12 : -5/-18

A = -5/12 - 7/12 x 18/5

A = -5/12 - 7/(2 x 6) x (3 x 6)/5

A = -5/12 - 7/2 x 3/5

A = -5/12 - 21/10

A = (-5 x 5)/(12 x 5) - (21 x 6)/(10 x 6)

A = -25/60 - 126/60

A = -151/60

B = (5/8 - 7/6) x (8/5 - (-3/35))

B = [(5 x 3)/(8 x 3) - (7 x 4)/(6 x 4)] x (8/5 + 3/35)

B = (15/24 - 28/24) x [(8 x 7)/(5 x 7) + 3/35]

B = (-13/24) x (56/35 + 3/35)

B = -13/24 x 59/35

B = (-13 x 59)/(24 x 35)

B = (-767/840)