9,73 * 1 3/7 - (1 3/5)² = 9 73/100 * 1 3/7 - (8/5)² =
= 973/100 * 10/7 - 64/25 = 139/10 - 64/25 = 695/50 - 128/50 = 567/50 =
= 11 17/50 = 11,34
2,8 / (7 - 3/9 * 7/15) = 2,8 / (7 - 7/45) = 2,8 / (315/45 - 7/45) =
= 2,8 / (308/45) = 28/10 : 308/45 = 28/10 * 45/308 = 2/2 * 9/22 = 9/22