Question

30-23,1:(5 720-4 635)

Answer 1

30 -23,1 : (5 7/20 - 4 6/35)=10 2/5 
1. 5 7/20 - 4 6/35= 5 49/140 - 4 24/140 = 1 25/140 = 1 5/28 
2. 23,1 : 1 5/28= 231/10 : 33/28= 231/10 * 28/33 = 98/5 = 19 3/5 
3. 30 - 19 3/5= 29 5/5 - 19 3/5 = 10 2/5 

Answer 2

30-23,1:(5 7/20-4 6/35)=30-23,1:(5 49/140-4 24/140)=30-23,1: 1 25/140=30-23,1:165/140=30-23,1*140/165=30-231/10*140/165=30-3234/165=30-19,6=10,4