Срочно!!! 75 баллов!
9/16 (4/5 - y) - (-1/20 - y) ("ц" - целое число, скажем 1 целая 8/15 (пример))

-8/21 * (7/16 + y) - (1/6 + y)

2ц 1/7а + 3ц 9/14а = 11ц 1/7 - 1ц 1/21 = 2ц 3/14

-3ц 2/5b - 1ц 1/20b = -3ц 1/10 + 1ц 4/5 - 2ц 7/20

9*4/16*5  - 9y/16  + 1/20 + y =9/20 + 1/20 + (- 9y +16y)/16 = 10/20 + 7y/16 = 7y/16  + 0.5 -8/21 * (7/16 + y) - (1/6 + y) = - 8*7/21*16 - 8y/21 - 1/6 -y = -1/6 -1/6 - (8y+21y)/21 = -2/6  - 29y/21  = -(1/3 + 29у/21)