(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)*(1-1/3)+(1/2)*(1/3-1/5)+(1/2)*(1/5-1/7)+...(1/2)*(1/99-1/101)
=(1/2)*(1-1/3+1/3-1/5+1/5-1/7+...1/99-1/101)
=(1/2)*(1-1/101)
=50/101
(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)*(1-1/3)+(1/2)*(1/3-1/5)+(1/2)*(1/5-1/7)+...(1/2)*(1/99-1/101)
=(1/2)*(1-1/3+1/3-1/5+1/5-1/7+...1/99-1/101)
=(1/2)*(1-1/101)
=50/101