Verified answer

50 - 23,1 : (5 7/20 - 4 6/35) = 30 целых 2/5 = 30,4

1) 5 7/20 - 4 6/35 = 5 49/140 - 4 24/140 = 1 25/140 = 1 целая 5/28

2) 23,1 : 1 5/28 = 231/10 : 33/28 = 231/10 · 28/33 = (7·14)/(5·1) = 98/5 = 19 3/5

3) 50 - 19 3/5 = 49 5/5 - 19 3/5 = 30 целых 2/5 - в обыкновенных дробях

3) 50 - 19 3/5 = 50 - 19 6/10 = 50 - 19,6 = 30,4 - в десятичных дробях