Вычислите(1целая1/4-2целых1/2*3/5): 4/5

(1_1/4 - 2_1/2 * 3/5 ) : 4/5 = - 5/16

           2          1         3

1) 2_1/2 * 3/5 = 5/2 * 3/5 = (5*3) / (2*5) = 3/2 = 1_1/2

2) 1_1/4 - 1_1/2 = 1_1/4 - 1_2/4 = -1/4

3) -1/ 4 : 4/5 = -1/4 * 5/4 = - (1*5) / (4*4) = - 5/16