Bonsoir, pouvez vous m'aidez svp? Merci d'avance

Bonsoir,

a) 3/9 + 5/2
= (3 x 2) / (9 x 2) + (5 x 9) / (2 x 9)
= 6/18 + 45/18
= 51/18
= (3 x 17) / (3 x 6)
= 17/6

b) 6/7 - 2/3
= (6 x 3) / (7 x 3) - (2 x 7) / (3 x 7)
= 18/21 - 14/21
= 4/21

c) 7/4 - 9/5
= (7 x 5) / (4 x 5) - (9 x 4) / (5 x 4)
= 35/20 - 36/20
= - 1/20

d) 3/8 + 1/7
= (3 x 7) / (8 x 7) + (1 x 8) / (7 x 8)
= 21/56 + 8/56
= 29/56

e) - 7/3 + - 1/4
= - 7/3 - 1/4
= (- 7 x 4) / (3 x 4) - (1 x 3) / (4 x 3)
= - 28/12 - 3/12
= - 31/12

f) 2/11 - 3/10
= (2 x 10) / (11 x 10) - (3 x 11) / (10 x 11)
= 20/110 - 33/110
= - 13/110