Упростите выражение 12 61/63-(11 11/28+3 13/86):(-15/28)+23

12 61/63 - (11 11/28 + 3 13/86) : (-15/28) + 23 = (12 * 63 + 61)/63 - ((11 * 28 + 11)/28 + (3 * 86 + 13)/86) : (-15/28) + 23 = (756 + 61)/63 - ((308 + 11)/28 + (258 + 13)/86) : (-15/28) + 23 = 817/63 - (319/28 + 271/86) * (-28/15) + 23 = 817/63 + 28/15 * 319/28 + 271/86 * 28/15 + 23 = 817/63 + 13717/645 + 3794/645 + 14835/645 = 817/63 + 10782/215 = 175655/13545 + 679266/13545 = 854921/13545 = 63,12.