Ответ Автор - MishaDiveev 1. 8 (x-y)/9 (y-x) = -8 (y-x)/9 (y-x) = -8/9 (C)2. 11 (a-b)/13 (b-a) = -11 (b-a)/13 (b-a) = -11/13 (D)3. 7 (a-b)/-8 (a-b) = -7/8 (A)