解:
(1+1/2)*(1-1/2)*(1+1/3)*(1-1/3)*...*(1+1/99)*(1-1/99)
=(1-1/2)(1+1/2)(1-1/3)(1+1/3)……(1-1/99)(1+1/99)
=(1/2)(3/2)(2/3)(4/3……(98/99)(100/99)
中间约分
=(1/2)x(100/99)
=50/99
原式=(3/2)*(1/2)*(4/3)*(2/3)*(5/4)*(3/4)*...*(99/98)*(97/98)*(100/99)*(98/99)
=(1/2)*(100/99)
=100/198