4 1 2 5 3
(19 - ( 12 2/7 - 6 3/5) * 2 1/3) + 9 1/5 : 5 1/2 = 7 67/165
1) 12 2/7 - 6 3/5 = (12 - 6) + (2/7 - 3/5) = 6 + (10/35 - 21/35) = 6 - 11/35 = 5 24/35
2) 5 24/35 * 2 1/3 = 199/35 * 7/3 = 199/15 = 13 4/15
3) 9 1/5 : 5 1/2 = 46/5 : 11/2 = 92/55 = 1 37/55
4) 19 - 13 4/15 = 5 11/15
5) 5 11/15 + 1 37/55 = 6 + (11/15 + 37/55) = 6 + (605/825 + 555/825) =
= 6 + 1160/825 = 6 + 1 335/825 = 7 67/165