计算1+1/1*2+1/2*3+1/3*4+.......+1/1999x2000
1/1*2=1-1/2,1/2*3=1/2-1/3,......
参考答案:计算1+1/1*2+1/2*3+1/3*4+.......+1/1999x2000
=1+1-1/2+1/2-1/3+1/3-1/4+...+1/1999-1/2000
=2-1/2000
=3999/2000
1/1*2=1-1/2,1/2*3=1/2-1/3,......
参考答案:计算1+1/1*2+1/2*3+1/3*4+.......+1/1999x2000
=1+1-1/2+1/2-1/3+1/3-1/4+...+1/1999-1/2000
=2-1/2000
=3999/2000