Выполните вычитание а)1 1\8-6\85 2\5-3\54 4\9-5\6б)3 7\16-1 5\86 2\15-3 2\312 5\8-5

а) 1 1/8 - 6/85 = 9/8 - 6/85 = 85 * 9/(8 * 85) - 8 * 6/(85 * 8) = (765 - 48)/680 = 717/680;

2/5 - 3/54 = 54 * 2/270 - 5 * 3/270 = (108 - 15)/270 = 93/270;

4/9 - 5/6 = 6 * 4/54 - 9 * 5/54 = (24 - 45)/54 = -21/54;

б) 3 7/16 - 1 5/86 = (3 * 16 + 7)/16 - (1 * 86 + 5)/86 = 55/16 - 91/86 = 86 * 55/1376 - 16 * 91/1376 = (4730 - 1456)/1376 = 3274/1376 = 1637/688;

2/15 - 3 2/312 = 312 * 2/(15 * 312) - 15 * (3 * 312 + 2)/(15 * 312) = (624 - 14070)/4680 = -2241/780;

5/8 - 5 11/12 = 12 * 5/96 - 8 * (5 * 12 + 11)/96 = (60 - 568)/96 = -127/24.