1. 3 5/12 - 4/5 + 31/60 = 41/12 - 4/5 +31/60
41/12 - 4/5 = (205 - 48) / 60 = 157/60
157/60 + 31/60 = (157 + 31) / 60 = 188/60 = 47/15 = 3 2/15
2.6 5/9 + 3 - 7/12 = 59/9 + 3 - 7/12
59/9 + 3 = (59 + 27) / 9 = 86/9
86/9 - 7/12 = (344 - 21) / 36 = 323/36 = 8 35/36
3. 8 7/15 - 5 3/4 + 6 = 127/15 - 23/4 + 6
127/15 - 23/4 = (508-245) / 60 = 163/60
163/60 + 6 = (163 + 180) / 60 = 343/60 = 5 43/60