Réponse :
Explications étape par étape :
1).
A. -5/6 + 2/4 - 1/12 = -10/12 + 6/12 - 1/12 = -5/12
B. 5/2 - 7/9 - 4/3 = 45/18 - 14/18 - 24/18 = 7/18
2).
A. 9/5 + 2/5 x 11/4 = 9/5 + 22/20 = 36/20 + 22/20 = 58/20 = 29/10
B. 8/3 - 8/3 x 9/16 = 8/3 - 72/48 = 128/48 - 72/48 = 56/48 =28/24= 14/12 = 7/6
C. 8/3 - 5/7 : 20/21 = 8/3 - 3/4 = 24/12 - 9/12 = 15/12
3).
B. [tex]\frac{1/4-1/5}{1/5-1/6} \\[/tex] = [tex]\frac{1/20}{1/30} = \frac{1}{3} = 1.5\\[/tex]
C. 2/3 - (-4/9+7/6) = 2/3 - (-29/18) = 12/18 + 29/18 = 41/18
