DM de maths à faire pour lundi svp

Bonsoir

A = 1/7 - 5/7 = - 4/7
B = 2/5 -3/4 = 8/20 - 15/20 = - 7/20
C = 3/4 x 7/11 = 21/44
D = -2/15 x 25/6 = - 50 / 90 = - 5/9
E = 4/7 : 5/3 = 4/7 x 3/5 = 12/35

104
A = 7/5 - 7/3 x 15/14
A = 7/5 - 5/2
A = 14/10 - 25/10 = - 11/10

B = 8/5 - 3/4 : 9/8
B = 8/5 - 3/4 x 8/9
B = 8/5 - 24/36
B = 8/5 - 2/3
b = 24/15 - 10/15 = 14/15

C = (8/3 -2/5) : 7/5
c = ( 40/15 - 6/15) : 7/5
C = 34/15 x 5/7 = 170/105 = 34/21

105

3/4 +1/5 = 15/20 + 4/20 = 19/20
1/20 représente la nage
1/20 = 100 m donc 20/20 = 100x 20 = 2 000 m

vélo = 2 000 x 3/4 = 1 500 m
course = 2 000 : 5 = 400 m
nage = 100 m