1) 3/15 - 2 7/25 = 3/15 - 57/25 = (15-171)/75= - 156/75
2) -156/75 : 27/25 = -156/75 * 25/27 = -52/27
3) -52/27 + 1 4/13 = -52/27 + 17/13 = (-676+459)/351=-217/351
2/3=20/30
7/10=21/30
1/3=10/30
1/10=3/30
Порядок убывания: 7/10, 2/3, 1/3, 1/10
3/26+1/6=9/78+13/78=22/78=11/39
37/39-11/39=26/39=2/3
17/20-7/24=102/120-35/120=67/120
27+67/120=27 67/120
y=1-9/26;
y=17/26
y= 45 75/90-45 27/60
y=45 150/180-81/180
y=69/180
y=23/60