1、原式=1-1/2+1/2-1/3+1/3-1/4+...+1/99-1/100
=1-1/100
=99/100
2、原式=1/2-1/3+1/2*(1/3-1/5+1/5-1/7+.+1/97-1/99+1/99-1/101)
=1/2-1/3+1/2*(1/3-1/101)
=1/3-1/202
=199/606
1、原式=1-1/2+1/2-1/3+1/3-1/4+...+1/99-1/100
=1-1/100
=99/100
2、原式=1/2-1/3+1/2*(1/3-1/5+1/5-1/7+.+1/97-1/99+1/99-1/101)
=1/2-1/3+1/2*(1/3-1/101)
=1/3-1/202
=199/606