a).numaratorul 7 iar numitorul cu 3 mai mic=7/4
b). numitorul 7 iar numaratorul cu 3 mai mare=10/7
c). numitorul numar prim par,iar fractia reprezinta zero parti dintr-un intreg=0/2
2.a).2/1;2/2; 2/3; 2/4; 2/5; 2/6; 2/7.
b).(2+3)/2=5/2; 6/2;4/2; 7/2;8/2;9/2,
c). 2/14, 2/21; 2/28; 4/14, 4/21, 4/28; 6/14, 6/21, 6/28; 8/14, 8/21, 8/28, 10/14, 10/21,10/28, 12/`14, 12/21, 12/28;
d). 20/10; 30/15; 40/20; 50/25; 60/30; 70/35, 80/40
3. a). 2/7=4/14=6/21=8/28=10/35=12/42
b).1/5=2/10=4/20=5/25=10/50=20/100
c)3/2=6/4=9/6=12/8=15/10