Ответ:
Сокращаем каждую дробь на её наибольший общий делитель.
- 52/91 = 4/7; 42/49 = 6/7; 40/72 = 5/9; 56/64 = 7/8; 21/91 = 3/13; 86/81 — несократимая дробь; 54/63 = 6/7; 18/38 = 9/19; 15/51 = 5/17; 57/76 = 3/4; 60/96 = 5/8; 4/6 = 2/3; 42/78 = 7/13; 39/91 = 3/7.
- 28/42 = 2/3; 18/51 = 6/17; 68/85 = 4/5; 42/54 = 7/9; 72/81 = 8/9; 15/65 = 3/13; 45/81 = 5/9; 82/40 = 41/20; 48/84 = 4/7; 84/85 — несократимая дробь; 49/84 = 7/12; 48/56 = 6/7; 27/57 = 9/19; 32/48 = 2/3; 12/— — знаменатель на изображении не виден.
- 20/45 = 4/9; 12/72 = 1/6; 136/170 = 4/5; 21/108 = 7/36; 24/36 = 2/3; 15/35 = 3/7; 102/136 = 3/4; 90/126 = 5/7; 3/39 = 1/13; 36/63 = 4/7; 21/84 = 1/4; 151/302 = 1/2; 130/182 = 5/7; 490/560 = 7/8; 10/— — знаменатель на изображении не виден.
- 48/68 = 12/17; 18/72 = 1/4; 24/70 = 12/35; 110/154 = 5/7; 36/60 = 3/5; 7/68 — несократимая дробь; 20/64 = 5/16; 112/144 = 7/9; 56/140 = 2/5; 10/85 = 2/17; 280/480 = 7/12; 17/51 = 1/3; 36/90 = 2/5; 13/65 = 1/5; 20/— — знаменатель на изображении не виден.
