Bonjour
a. 2/5 : 9/11
= 2/5 x 11/9
= 22/45
b. 3/7 : 8/13
= 3/7 x 13/8
= 39/56
c. 5/8 : 9/17
= 5/8 x 17/9
= 85/78
d. 3/2 : 7/5
= 3/2 x 5/7
= 15/14
e. 3 : 2/7
= 3 x 7/2
= 21/2
f. 15/4 : 7
= 15/4 x 1/7
= 15/28
a. - 7/6 : 3/4
= - 7/6 x 4/3
= - 28/18
= (2 x - 14) / (2 x 9)
= - 14/9
b. 3/8 : - 3/4
= 3/8 x - 4/3
= - 12/24
= (12 x - 1) / (12 x 2)
= - 1/2
c. - 5/9 : - 8/3
= - 5/9 x - 3/8
= 15/72
= (3 x 5) / (3 x 24)
= 5/24.