:15/17+1/17-7/17 7/8-3/8+1/8 49/100-29/100+11/100 47/50+3/50-7/50 111/120-51/60+7/30 69/100+11/25-4/5

15/17+1/17-7/17=9/17
7/8-3/8+1/8=5/8
49/100-29/100+11/100=31/100
47/50+3/50-7/50=43/50
111/120-51/60+7/30=111/120-102/120+28/120=37/120
69/100+11/25-4/5=68/100+44/100-80/100=32/100