ВЫЧИСЛИТЕ(-2,5-1 5/6)÷ 1 4/9- 3 4/9×(-2 1/4)

(- 2,5 - 1 5/6) ÷ 1 4/9 - 3 4/9 × (- 2 1/4) = 4 3/4.

1). - 2,5 - 1 5/6 = - 2 5/10 - 11/6 = - 25/10 - 11/6 = - (25 * 3)/(10 * 3) - (11 * 5)/(6 * 5) = - 75/30 - 55/30 = - (75 + 55)/30 = - 130/30 = - 13/3 = - 4 1/3; 2). - 4 1/3 : 1 4/9 = - 13/3 : 13/9 = - 13/3 * 9/13 = - (13 * 9)/(3 * 13) = - 9/3 = -3; 3). 3 4/9 * ( - 2 1/4) = 31/9 * (- 9/4) = - (31 * 9)/(9*4) = -31/4 = - 7 3/4; 4). - 3 - ( -7 3/4) = - 3 + 7 3/4 = 4 3/4. 

Ответ: 4 3/4.