Can someone please tell me the formula for pv benefits and pv costs?

BENEFTIS Benefit - Healthcare Cost Reduction per App Unit S199 COSTS $36,500 Development Costs Onetime Development Costs - Developer Trainin Development Cost - Maintenance Development Cost Sala Apple Developer License Advertising $1,798 $1,000 $95,000 $99 $2,400 NPV ANALYSIS Benefits $0 89,550 107,460 128,952 154,742 185,691 YearApp Units Costs PV Benefits PV Costs PV Cash Flow 450 540 648 778 933 $36,500 99,297 98,499 98,499 98,499 98,499 S0$36,500 95,939 91,950 88,840 85,836 82,934 NPV 36,500 9,417 8,365 27,467 49,013 73,413 112,341 1 86,522 100,315 116,307 134,849 156,347 4