The 5,000 impacts operating cash flows (Costs), so we would subtract it from OCF.

Solution 2

NCS = [Cashflow(-100000,0,.05)]
OCF = [Cashflow(45000,1,.05),Cashflow(45000,2,.05),Cashflow(45000,3,.05),Cashflow(45000,4,.05),Cashflow(45000,5,.05)]
print(NPV(NCS)+NPV(OCF))