Réponse :
EXERCICE 1
1.
1. a. A = 24 + 6 : 2 = 24 + 6/3 = 24 + (2x3)/(1x3) = 24 + 2/1 = 26
b. B = 18 : 4 - 2 = 18/4 - 2 = (2x9)/(2x2) - 2 = 9/2 - 2 = 9/2 - 4/2 = 5/2
c. C = (24 + 6) : 2 = 30 :2 = 30/2 = (15x2)/(1x2) = 15
EXERCICE 2
1. F1 = 56/64 = (7x8)/(8x8) = 7/8
2. F2 = 63/75 = (3x21)/(3x25) = 21/25
3. F3 = 28/49 = (4x7)/(7x7) = 4/7
4. F4 = (6x15)/(6x35) = 15/35 = (5x3)/(5x7) = 3/7
EXERCICE 3
1. 12/13 = 0,92
12/15 = (3x4)/(3x5) = 4/5 = 0,8
2. 111/37 = 3
99/37 = 2,6
3. 137/47 = 2,91
47/137 = 0,34
4. 2/3 = 0,66
3/4 = 0,75
Explications étape par étape