1         2     5        3        4

(7-1 5/12):6,7+(5,75-3 1/6):15,5=

1) 7-1 5/12=6-5/12=5 12/12-5/12=5 7/12

2) 5 7/12:6,7= 5 7/12:6 7/10=67/12:67/10=67/12*10/67=10/12=5/6

3) 5,75-3 1/6=5 75/100-3 1/6=5 3/4-3 1/6=                                                           2 3/4-1/6=11/4-1/6=33/12-2/12=31/12

4) 31/12:15,5=31/12:15 1/2=31/12:31/2=31/12*2/31=1/6

5) 5/6+1/6=6/6=1