Réponse :
Bonsoir
Explications étape par étape :
A = (496/806) - (3/26)
A = (31*2*8/31*2*13) - (3/26)
A = (8/13) - (3/26)
A = (16/26) - (3/26)
A = (16-3)/26
A = 13/26
A = 1/2
B = 5/6 + 3/4 ÷ 11/6
B = 5/6 + 3/4 * 6/11
B = 5/6 + (3*2*3/2*2*11)
B = 5/6 + 9/22
B = 55/66 + 27/66
B = 82/66
B = (2*41)/(2*33)
B = 41/33
C = 15/49 * 34/165 * 77/136
C = (5*3*2*17*7*11)/(7*7*5*3*11*17*4*2)
C = 1/28