bonjour
A = 5/12 + 5/6 - 1 /2
= 5/12 + 10/12 - 6/12
= 9/12
= 3/4
B = 1/3 + 5/3 x 2/7
= 1/3 + 10/21
= 7/21 + 10/21
= 17/21
C = - 4/7 : - 3/5
C = - 4/7 x - 5/3
= 20/21
