呵呵,几分之几可以用斜杠/表示,相当于除以所以可以表示为1/2-1/6-1/12-1/20-1/30.-1/9900=1/2-(1/6+1/12+1/20+1/30...+1/9900)=1/2-(1/(2*3)+1/(3*4)+1/(4*5)+1/(5*6)...+1/(99*100))=1/2-((1/2-1/3)+(1/3-1/4)+(1/4...