Bonjour
16)
A = 3/7 + 2/7 = 5/7
B= -5/3+ 7/3
B=2/3
C = 4/5,3 - 7/5,3
C= - 3/5,3
D = - 4/8 + - 7/8
D = - 11/8
17)
A = 6/4 - 11/4
A = - 5/4
B = 3/11 - 7/11
B = - 4/11
C = 2/9 - - 5/9
C= 2/9 + 5/9
C= 7/9
D = - 11/7 - - 5/7
D= - 11/7 + 5/7
D= - 6/7.
