(1/101-1)*(1/100-1)*(1/99-1).(1/2-1)

问题描述:

(1/101-1)*(1/100-1)*(1/99-1).(1/2-1)

(1/101-1)*(1/100-1)*(1/99-1).(1/2-1)
=(-100/101)*(-99/100)*(-98/99).(-1/2)
=100/101*99/100*98/99...*1/2
=1/101(101分之1一1)*(100分之1一1)*(99分之1-1)......(2分之1-1)=101分之1一1 =-100/101没错啊