Bonsoir,
A = 3/7 * (7/3 - 5/6)
A = 3/7 * (14/6 - 5/6)
A = 3/7 * 9/6
A = 3/7 * 3/2
A = 9/14
B = 3/7 * 7/3 - 5/6
B = 21/21 - 5/6
B = 1 - 5/6
B = 6/6 - 5/6
B = 1/6
C = 12 * (1/3 - 1/6)
C = 12 * (2/6 - 1/6)
C = 12 * 1/6
C = 12/6 = 2
D = 12 * 1/3 - 1/6
D = 12/3 - 1/6
D = 4 - 1/6
D = 24/6 - 1/6
D = 23/6