题目应是(1-2^2/1）（1-3^2/1)(1-4^2/1)…(1-99^2/1)(1-100^2/1)
=(1-2/1)(1+2/1)(1-3/1)(1+3/1).(1-99/1)(1+99/1)(1-100/1)(1+100/1)
=(1-2/1)(1-3/1).(1-99/1)(1-100/1)(1+2/1)(1+3/1).(1+99/1)(1+100/1)
=(2/1)(3/2).(99/98)(100/99) (2/3)(3/4).(99/100)(100/101)
=(100/1) (2/101)
=200/101