7/3+5/6=(2·7+5)/6=(14+5)/6=19/6
15/18+7/12+4/9=
calculam c.m.m.m.c
18=3²·2
12=3·2²
9=3²
[18,12,9]=2²·3²=36
36:18=2, 36:12=3, 36:9=4
15/18+7/12+4/9=(2·15+7·3+4·4)/36=(30+21+16)/36=67/36
5/14+3/7=(5+3·2)/14=11/14
7/8+5/18+1/6=
8=2³
18=2·3²
6=2·3
[8,18,6]=2³·3²=72
7/8+5/18/+1/6=(7·9+5·4+1·12)/72=(63+20+12)/72=95/72
