3+ 8,5/12= 3 + 8 5/10 :12 = 3+ 85/10 :12 = 3+ 85/10 * 1/12 = 3 + 85/120 = 3+ 17/24 = 3 17/24 10,6/7-3= 10 6/10: 7 - 3= 106/10:7 - 3 = 106/10 *1/7 - 3= 106/70 - 3 = 53/35-3= -1 17/35 = - 1,49 4,2/13+5,7/13=4 2/10 :13 + 5 7/10:13 = 42/10:13 + 57/10: 13 = 99/10: 13 = 99/10 *1/13 = 99/130 =0,76 8/7,12-4,2/12= 8: 7 12/100 - 4 2/10: 12= 8: 712/100 - 42/10: 12 = 8 * 100/712 - 42/10* 1/12 = 800/712 - 42/120 = (24000-7476)/21360 = 4131/5340 = 0,77 4,8/11+5,7/11= 4 8/10 :11 + 5 7/10 :11 = 48/10:11 + 57/10: 11 = 105/10 :11= 105/10 * 1/11 = 105/110 = 21/22 = 0,95 7,5/9-2,8/9 = 7 5/10: 9 - 2 8/10: 9 = 75/10:9 - 28/10: 9 = 47/10: 9= 47/10 * 1/9 =47/90 = 0,52 7-3/8= 6 5/8 = 6,63 10-3,7/15 = 10- 3 7/10:15 = 10- 37/10:15 = 10 - 37/10*1/15= 10- 37/150 =9 113/150 = 9,75