Ответ:

14/35 * 25/49 = 2/7 * 5/7 = 10/49;

8 2/21 * 7 = 170/21 * 7 = 170/3 * 1/1 = 170/3 = 56 2/3;

4 4/11 * 4 7/12 = 48/11 * 55/12 = 4/1 * 5/1 = 20/1 = 20;

(1 1/4)^2 = (5/4) = 5^2 / 4^2 = 25/16 = 1 9/16;

1 7/56 * 3 8/9 — 2,7 = 63/56 * 35/9 = 7/8 * 5/1 = 35/8 = 4 3/8.