Réponse :
Explications étape par étape
* 1/3 + 1/7 = (7 + 3 ) / 21 = 10/21
* 2 . 5/3 = 10/3
* -2/3 + 1/6
= (-2 . 2) + 1 / 6
= (-4 +1 ) / 6
= -3 / 6
* 2/3 . 2/5 = 4/15
* -2/3 . 1/6 = -1/3 . 1/3 = - 1/9
* 1/4 + 7/4 . 1/7
= 1/4 + 1/4
= 1/2
* 3/4 . 5/4 - 1/8
=15/16 - 1/8
= 13/16
* 2/7 . (1/4 - 3/10) parenthèse en premier
=2/7 . ( -1/20)
= 1/7 . -1 /10
=- 1 / 70
* 3/5 / 2/15
= 3/5 . 15 /2
= 9/2
