Sagot :

Bonjour,

5/15 + 6/15 = 11/15

12/28 + 7/28 = 19/28

6/21 + 35/21 = 41/21

-3/12 + 4/12 = 1/12

-10/35 + 7/35 = -3/35

kiwia

1/3 + 2/5 = 1×5/3×5 + 2×3/5×3 = 5/15 + 6/15 = 11/15

3/7 + 1/4 = 12/28 + 7/28 = 19/28

2/7 + 5/3 = 6/21 + 35/21 = 41/21

-1/4 + 1/3 = 1/3 - 1/4 = 4/12 - 3/12 = 1/12

-2/7 + 1/5 = -10/35 + 7/35 = -3/35