Bonsoir,
A = 1/3 + 5/4
A = (1 x 4) / (3 x 4) + (5 x 3) / (4 x 3)
A = 4/12 + 15/12
A = 19/12
B = 15/28 x 7/25 x 1/6
B = 105/700 x 1/6
B = 105/4 200
B = (105 x 1) / (105 x 40)
B = 1/40
C = 24/7 - (- 12)
C = 24/7 + (12 x 7) / (1 x 7)
C = 24/7 + 84/7
C = 108/7
