Bonjour
1-Classer les fractions suivantes après les avoir simplifiées :
a = −39/52 = (13 x - 3) / (13 x 4) = -3/4 = (- 3 x 5) / (4 x 5) = - 15/20
b = 62/217 = (31 x 2) / (31 x 7) = 2/7 = (2 x 9) / (7 x 9) = 18/63
c =58/261 = (29 x 2) / (29 x 9) = 2/9 = (2 x 7) / (9 x 7) = 14/63
d = − 42/70 = (14 x - 3) / (14 x 5) = - 3/5 = (- 3 x 4) / (5 x 4) = - 12/20
e =48/84 = (12 x 4) / (17 x 7) = 4/7 = (4 x 9) / (7 x 9) = 36/63
Donc :
- 39/52 < - 42/70 < 58/261 < 62/217 < 48/84
2- Calculer les nombres suivants
a =2/15 ×3/5−28/2×7/20 + 11 ×6/275
= 6/75 - 196/40 + 66/275
= (3 x 2) / (3 x 25) - (4 x 49) / (4 x 10) + (11 x 6) / (11 x 25)
= 2/25 - 49/10 + 6/25
= 8/25 - 49/10
= (8 x 2) / (25 x 2) - (49 x 5) / (10 x 5)
= 16/50 - 245/50
= - 229/50
b= (7/12 + 3/4) : 2/3 : (8/15 - 7/20) : (4/5 + 3/14)
b = [7/12 + (3 x 3) / (4 x 3)] : 2/3 : [(8 x 4) / (15 x 4) - (7 x 3) / (20 x 3)] : [(4 x 14) / (5 x 14) + (3 x 5) / (14 x 5)]
b = (7/12 + 9/12) : 2/3 : (32/60 - 21/60) : (56/70 + 15/70)
b = 16/12 : 2/3 : 11/60 : 71/70
b = 16/12 x 3/2 x 60/11 : 71/40
b = 48/24 x 60/11 : 71/40
b = 2860/264 : 71/40
b = (44 x 65) / (44 x 6) : 71/40
b = 65/6 x 40/71
b = 2600/426
b = (2 x 1300) / (2 x 213)
b = 1300/213.
