Réponse :
bonjour
a. 10/9 - 5/ 9 x 5/3 = 10/9 - 25 /27 = 30/27 - 25/27 = 5 /27
b . ( 22/8 - 2 /8 ) x - 7 /10 = 20 /8 * - 7 /10 = - 140/80 = - 7/4
c = - 11/21 - 3 /7 x 3 = - 11/21 - 9/7 = - 11/21 - 27/21 = - 16/21
a = 1 /3 * 2/21 * 9/14
= ( 1 * 2 * 9 ) / ( 3 * 21 *14 ) = 18/882 = 1/49
b = 4/9 + 2/18 - 4/18 = 8/18 + 2/18 - 4/18 = 6/18 = 1/3
c = 14/12 - 5 /8 * 7/3
= 14/12 - 35/24
= 28/24 - 35/24
= - 7/24
Explications étape par étape :
