Bonsoir :)
Réponse en explications étape par étape :
- Question : Simplifier, puis effectuer les calculs :
A = 25/21 * 14/15
A = (25 * 14)/(21 * 15)
A = (5 * 5 * 7 * 2)/(3 * 7 * 5 * 3)
A = (5 * 2)/(3 * 3)
A = 10/9
B = - 21/6 * - 9/56
B = 21/6 * 9/56
B = (21 * 9)/(6 * 56)
B = (7 * 3 * 3 * 3)/(3 * 2 * 7 * 8)
B = (3 * 3)/(2 * 8)
B = 9/16
C = - 49/63 * 9/- 28
C = - 49/63 * - 9/28
C = 49/63 * 9/28
C = (49 * 9)/(63 * 28)
C = (7 * 7 * 3 * 3)/(7 * 3 * 3 * 4 * 7)
C = 1/4
Voilà
