Bonsoir
702/2 = 351
351/3 =117
117/3 = 39
39/3 =13
=> 2*3*3*3*13
396/2 =198
198/*2= 99
99/3 = 33
33/3= 11
=> 2*2*3*3*11
702/396 =
On divise par 2*3*3 = 18 ( diviseurs communs) => 39/22
-7/28 = -1/4
-13/-26 = 1/2
315/80 = 63/16
42/-40 = 21/-20
-65/105 = -13/21