5-(2/3+14/15+34/35+62/63+98/99)=1/3+1/15+1/35+1/63+1/99=1/2(2/3+2/15+2/35+2/63+2/99)=1/2{(1-1/3)+(1/3-1/5)+(1/5-1/7)+(1/7-1/9)+(1/9-1/11)}=1/2(1-1/11)=5/112/3+14/15+34/35+62/63+98/99=5-5/11=50/11.（插...
