1-1/2= 1-1/2-1/4= 1-1/2-1/4-1/8= 算一算,找规律

(1-1/2)*(1-1/3)*(1-1/4)*...*(1-1/99)*(1-1/100)= 1/2+1/3+1/4=? 1/2-3/1-4/1= 1+1/2+1/4+1/8+...1/64=? （1-1/2)+(1/2-1/3)+(1/3-1/4)+.+(1/1999-1/2000)= (1+1/2)*(1-1/2)*(1+1/3)*(1-1/3)*(1+1/4)*(1-1/4)*(1+1/5)*(1-1/5)=? （1+1/2)(1+1/2^2)(1+1/2^4）（1+1/2^8)+1/2^15=? 1*1/2=? 1+1=2? 1+1=2? 1+1×2=? 2-1=1 1/2+1/4+1/8+...+1/2n=? 巧算：(1+1/2+1/3+1/4+1/5)*(1/2+1/3+1/4+1/5+1/6)-(1+1/2+1/3+1/4+1/5+1/6)*(1/2+1/3+1/4+1/5)(1+1/2+1/3+1/4+1/5)*(1/2+1/3+1/4+1/5+1/6)-(1+1/2+1/3+1/4+1/5+1/6)*(1/2+1/3+1/4+1/5)===== 1+(1/1+2)+(1/1+2+3)+(1/1+2+3+4)+(1/1+2+3+4+...+100)=? 求和：sn=1/2^2-1+1/4^2-1+.1/(2n)^2-1 (1+1/2)(1+1/3)(1+1/4)...(1+1/2009)= (1-1/2)乘(1-1/3)乘(1-1/4).乘(1-1/2000)=?