1/1*2+1/2*3+1/3*+...1/101*102=
1/1*2+1/2*3+1/3*+...1/101*102=
1+2+3+...+55+56+...+99+100+101+102=
1/(1+2+3)+1/(4+5+6)+.+1/(100+101+102) =?
(1-2)×(2-3)×(3-4)×.×(101-102)×(102-103)=?
计算1*2 +2*3+...+100*101=?1*2*3+2*3*4+...+100*101*102=?1*2*3*4
1 2 3 .99 100 2 3 4 .100 101 3 4 5 .101 102 .100 101 102 .19
(-1)+2+(-3)+4+(-5)+6+.+(-99)+100+(-101)+102
1+2+3+4+5+.+100+101+102+103
101-102=1
1-1/2+1/3-1/4+1/5-1/6+…+1/99-1/100 1/(101+1)+1/(2+102)+1/(3+
谁般偶求下,感激不尽1/(1*2*3)+1/(2*3*4)+1/(3*4*5)...+1/(100*101*102)
(1-1/2+1/3-1/4+1/5-...+1/99-1/100)/[1/(1+101)+1/(2+102)+1/(3