1/2+3/4+7/8+...+1023/1024=1-1/2+1-3/4+.1-1/1024=10-(1/2+1/4+1/8+...+1/1024)=10-(1/2-1/1024*1/2)/(1-1/2)=10-(1-1/1024)=9+1023/10241/1*4+1/4*7+1/7*10+...+1/97*100 =1/3(1-1/4+1/4-1/7...+1/97+1/100)=1/3*9...