每年折旧=(450000-120000)/5=66000
NCF0=-450000
NCF1=-200000+(320000-150000-66000)*(1-40%)+66000=-71600
NCF2=-120000+(450000-210000-66000)*(1-40%)+66000=50400
NCF3=(450000-210000-66000)*(1-40%)+66000=170400
NCF4=NCF3=170400
NCF5=120000+200000+120000+(450000-210000-66000)*(1-40%)+66000=610400