35)

Tu dois juste mettre les fractions sous le même dénominateur:

1/2 + 1/4

= 1x2/2 x 2 + 1/4

= 2/4 + 1/4

= 3/4

5/6 + 5/12

= 5 x 2/6 x 2 + 5/12

= 10/12 + 5/12

= 15/12

= 3 x 5/3 x 4

= 5/4

13/14 + 5/7

= 13/14 + 5 x 2/7x2

= 1314 + 10/14

= 23/14

3/4 + 5/24

= 3x6/4 x 6 + 5/4

= 18/24 + 5/24

= 23/24