1) (1 целых 3/5 + 1,8) * 1/2

2) (6 - 4 целых 8/15) : 2,2

3) (1,25 + 1/6) * 2,4

1) (1 целая 3/5 + 1,8) * 1/2 = 1,7

1 целая 3/5 + 1,8 = 8/5 + 18/10 = 8/5 + 9/5 = 17/5

17/5 * 1/2 = 17/10 = 1,7

2) (6 - 4 целых 8/15) : 2,2 = 2/3

6 - 4 цел 8/15 = 5 цел 15/15 - 4 цел 8/15 = 1 целая 7/15

1 цел 7/15 : 2,2 = 22/15 : 22/10 = 22/15 * 10/22 = 10/15 = 2/3

3) (1,25 + 1/6) * 2,4 = 3,4

1,25 + 1/6 = 1 цел 1/4 + 1/6 = 1 цел 3/12 + 2/12 = 1 цел 5/12

1 цел 5/12 * 2,4 = 17/12 * 24/10 = (17*2) / (1*10) = 34/10 = 3,4