Bonjour,
2)
24/18 = (6 x 4) / (6 x 3) = 4/3
- 50/20 = (10 x - 5) / (10 x 2) = - 5/2
4/8 = (4 x 1) / (4 x 2) = 1/2
200/50 = (50 x 4) / (50 x 1) = 4
- 9/18 = (9 x - 1) / (9 x 2) = - 1/2
- 14/- 18 = (2 x 7) / (2 x 9) = 7/9
169/26 = (13 x 13) / (13 x 2) = 13/2
et
25/- 10 = (5 x - 5) / (5 x 2) = - 5/2
36/9 = (9 x 4) / (9 x 1) = 4
- 3/6 = (3 x - 1) / (3 x 2) = - 1/2
2/4 = (2 x 1) / (2 x 2) = 1/2
70/90 = (10 x 7) / (10 x 9) = 7/9
40/30 = (10 x 4) / (10 x 3) = 4/3
65/10 = (5 x 13) / (5 x 2) = 13/2
Donc :
24/18 → 40/30
- 50/20 → 25/- 10
4/8 → - 3/6
200/50 → 36/9
- 9/18 → - 3/6
- 14/- 18 → 70/90
169/26 → 65/10
3) 1-
1 - (1/4 + 2/3)
= (1 x 12) / (1 x 12) - [(1 x 3) / (4 x 3) + (2 x 4) / (3 x 4)]
= 12/12 - (3/12 + 8/12)
= 12/12 - 11/12
= 1/12
Il reste 1/12 de tarte après le passage de ces deux voraces.
2-
1 - (1/3 + 3/7)
= (1 x 21) / (1 x 21) - [(1 x 7) / (3 x 7) + (3 x 3) / (7 x 3)]
= 21/21 - (7/21 + 9/21)
= 21/21 - 16/21
= 5/21
5/21 du triathlon a été effectué en course à pied, soit en 40 minutes.
40 x 21/5 = 168 min
168 : 60 = 2,8 h et 0,8 x 60 = 48 min.
L'intégralité de son triathlon a duré 2 h 48 min.
