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