bonsoir pourriez vous m'aider s'il vous plait ?

56/24 : 2
= 56/24 x 1/2
= 56/48
= 8 x 7 / 8 x 6
= 7/6

11/15 + 2/3 x 4/5 - 4/15
= 11/15 + 8/15 - 4/15
= 19/15 - 4/15
= 15/15
= 1

4 % = 4/100

1 - 6/19 x 3
= 1 - 18/19
= 1 x 19 / 1 x 19 - 18/19
= 19/19 - 18/19
= 1/19

3/4 x 1/12
= 3/48
= 3 x 1 / 3 x 1 6
= 1/16