1/3+2/3=3/3=1
1/7+2/7+3/7=6/7
1/36+5/36=6/36=1/6
5/111+4/111=9/111
2.
1/5+2/5=3/5
1/7+3/7=4/7
3/8+2/8=5/8
1/9+2/9+4/9=7/9
3+1/2=6+1totul pe2=7/2
2si3/7+1/7+2/7=17/7+1/7+2/7=20/7
1si1/11+2si2/11+3si3/11+4si4/11=12/11+24/11+36/11+48/11=120/11
1si1/17+2si1/17+3si1/17+4si1/17+5si1/17=18/17+35/17+52/17+69/17+86/17=260/17