1) (3\4 + 1\5 ) x 5\19= 2) (12целых 1\3 - 7целых 3\4) х 5\19= 3) (2целых 3\5 - 5\8) : 19целых 3\4= 4) 9целых 2\7 х 1целую 2\5 : 13+6целых 3\7=

1) ( 3/4 + 1/5 ) * 5/19 = ( 15/20 + 4/20) * 5/19 = 19/20 * 5/19 = 5/20 = 1/4 
2) ( 12.1/3 - 7.3/4 ) * 5/19 = ( 12.4/12 - 7.9/12) * 5/19 = ( 11.16/12 - 7.9/12) * 5/19 
    = 4.7/12 * 5/19 = 55/12 * 5/19 = 275/228 = 1.47/228 
3) ( 2.3/5 - 5/8) : 19.3/4 = ( 2,6 - 0,625) : 79/4 = 1,975 : 19,75 = 0,1 
4) 9.2/7 * 1 2/5 : 13 + 6.3/7 = 65/7 * 7/5 : 13 + 45/7 = 65/5 : 13 + 45/7 =
   = 13 : 13 + 45/7 = 1 + 45/7 = 1 + 6.3/7 = 7.3/7