№1.
1) 5/7 * 2 1/3 = 5/7 * 7/3 = 5/3
2) 5/3 * 5/6 = 25/18 = 1 7/18
3) 17/18 - 1 = 7/18
4) 7/ 8 * 1 3/5 = 7/8 * 7/8 * 8/5 = 7/5
5) 7/5 * 3/14 = 3/10
6) 1-0,3=0,7
7) 7/18 : 7/10 = 7/18 * 10/7 = 5/9
№2.
1) 8 7/15 - 3 3/4 + 4 2/5 - 8 7/60 = 8 28/60 - 3 45/60 + 4 24/60 - 8 7/60 = 7 88/60 - 3 45/60 + 4 24/60 - 8 7/60 = 4 43/60 + 4 24/60 - 8 7/60 = 8 67/60 - 8 7/60 = 60/60=1
2) 4 1/4 - 2 3/4 = 4,25-2,75=1,5
3) 1:1,5=10/15=2/3
№3.
1) 1 8/13 * 13/42 = 21/13 * 13/42 = 1/2=0,5
2) 5 5/7 : 8/21 = 40/7 : 8/21 = 40/7 * 21/8 = 15
3) 0,5+15=15,5
4) 8 1/8 + 3 1/2 = 8,125+3,5=11,625
5) 15,5:11,625=15500/11625=3100/2325=620/465=124/93=4/3 = 1 1/3
№4.
1) 5 5/7 - 5 1/16 = 5 80/112 - 5 7/112 = 73/112
2) 2 3/5 : 6 1/15 = 13/5 : 91/15 = 13/5 * 15/91 = 3/7
3) 1 39/73 * 73/112 = 112/73 * 73/112=1
4) 3/7 + 1 1/14 - 1 = 6/14 + 1 1/14 - 1 = 1 7/14 - 1 = 7/14 = 1/2 =0,5