Пошаговое объяснение:

1) 5,4 * (-3 1/93) = 54/10 * (-280/93) = 54/1 * (-28/93) = -1512/93 = -16 8/31

2) -16 8/31 + 13,8 = -16 8/31 + 13 8/10 = -16 80/310 + 13 248/310 = -15 390/310 + 13 248/310 = -2 142/310 = -2 71/155

3) -2 71/155 : 1 13/15 = -381/155 : 28/15 = -381/155 * 15/28 = -381/31 * 3/28 = -1143/868 = -1 275/868

4) -1 275/868 + 3 5/6 = 2 1345/2604