Bonjour !
A = 8/5 + 7/5 x 3/5
A = 8/5 + (7*3)/(5*5)
A = 8/5 + 21/25
A = (8*5)/(5*5) + 21/25
A = 40/25 + 21/25
A = 61/25
B = 53/30 - (6/10 + 8/10)
B = 53/30 - 14/10
B = 53/30 - (14*3)/(10*3)
B = 53/30 - 42/30
B = 11/30
J'espère t'avoir aidé. Bon courage !
