Одно обстоятельство требует уточнения. 3/5 +(−16 2/1 + 16/15 ⋅12 5/4 ):2,7

(3/5) + (-16(1/2) + (15/16) * 12(4/5)) / 2,7.

(15/16) * 12(4/5) = (15/16) * (64/5) = 12.

-16(1/2) + 12 = -4,5 = -4(1/2) = -9/2.

(-9/2)/2,7 = (-9/2) / (27/10) = (-9/2) * (10/27) = -5/3.

(3/5) – (5/3) = (9 – 25)/15 = -16/15 = -1(1/15).

Ответ: -1(1/15).