Sagot :
Réponse :
A = 2/3 - (7/3 X 8) / 21
= 2/3 - (7/21 X 8/3) (Parce, (7/3 X 8)/21 = (8/3 X 7)/21 = 8/3 X 7/21)
= 2/3 - (1/3 X 8/3) (Parce, 7/21 = 1/3)
= 2/3 - 8/9
= 6/9 - 8/9
= -2/9
___________
B = ((3/4 - 5/6) X 3) / 2
= ((9/12 - 10/12) X 3) / 2
= (-1/12 X 3) / 2
= (-1/4)/2
= -1/8
____________
C = ((24/15 + 35/25) X 20) / 33
= ((8/5 + 7/5) X 20) / 33 (Parce, 24/15 = 8/5 et 35/25 = 7/5)
= ((15/5) X 20) / 33
= (3 X 20)/33
= 60 / 33 = 20/11 (60/33 = 20/11)
_____________
D = (5/6 - 5/4) / (1/2 + 2/3)
= (10/12 - 15/12) / (3/6 + 4/6)
= (-5/12) / (7/6)
= (-5/12) X 6/7
= -5/2 X 1/7
= -5/14
Voíla