Ex 1 :
A = 3/8 - 5/2 + 1/6
A = 9/24 - 60/ 24 + 4/24
A = -47/24
B = 3/5 - (-7/15) + 2
B = 9/15 + 7/15 + 2/1
B = 16/15 + 30/15
B = 46/15
Ex 2 :
Nous avons :
7/20
1/5 = 4/20
1/20
1/4 = 5/20
donc 7/20 + 4/20 + 1/20 + 5/20 = 17/20
Il fait donc 3/20 en nage libre
Ex 3 :
1/9 = 4/36
5/12 = 15/36
4/36 + 15/36 = 19/36, il reste donc 17/36 de jardin
Ex 4 :
7/5 = 1.4m
2/3 = 0.66m
3m - 1.4m + 0.66m = 3m - 2.06m = 0.94m
