(2 13/48+2 2/15):3 3/4-9 3/4:12

1) 2 13/48 + 2 2/15 = 2 65/240 + 2 32/240 = 4 97/240

2) 4 97/240 : 3 3/4 = 1057/240 : 15/4 = 1057/240 * 4/15 = 1057/900 = 1 157/900

3) 9 3/4 : 12 = 39/4 * 1/12 = 39/48 = 13/16

4) 1 157/900 - 13/16 = 1 628/3600 -  2925/3600 = 1303/3600