Réponse :
Bonjour,
A= 2- 25/9 = 2*9 / 1*9 - 25 / 9 = 18-25/9 = -7/9
B= 2/7 - 7 = 2/7 - 7*7 / 1*7 = 2- 49 / 7 = -47/7
C= 5/3 - 10*3/ 1*3 = 5/3 - 30 /3 = -25 / 3 =
D = 11/9 - 5/4 + 5*4 / 1*4 = 11/9 - 5+ 20 / 4 = 11 / 9 - 25 /4 = 11*4 / 9*4 - 25 * 9 / 4* 9 = 44-225 / 36 = -181 / 36
E = 5/3 -5/6 + 5/9 = 5*2 / 3*2 - 5/6 + 5/9 = 10 -5 / 6 + 5/9 = 5/6 + 5/9 = 45/54 + 30 / 54 = 75/54
