Bonsoir,
a)
3-2/3 = 9/3 -2/3 = 7/3
4/3 * 7 = 28/3
=> (7/3 )/ (28/3)
= 7/3 * 3/28
= 21/84 = 7/28 = 1/4
erreur corrigée
b)
(2/3)/ (5/6 ) -2/5
= 2/3 * 6/5 -2/5
= 12/15 -2/5
= 12/15- 6/15
=6/15 =2/5
c)
-3/4 +1/2 = -3/4 + 2/4 = -1/4
2/5 -5/2 = 4/10 - 25/10 = -21/10
(-1/4) / (-21/10 ) = (1/4)/ (21/10)
= 1/4 * 10/21
= 10/ 84 = 5/42
