I have this question that I believe I might have the right formula and information is in color BLUE. I just need to know what steps to take next. thank you

2. Machine A costs $350,000 to purchase, result in electricity bills of $100,000 per year, and last for 10 years. Machine B costs $550,000 to purchase, result in electricity bills of $80,000 per year, and last for 15 years. The discount rate is 12%.

What are the equivalent annual costs for two models?

Which model is more cost-effective?

cost

electricity bill $

years

Discount rate

Machine A

350,000

100,000

10

12%

Machine B

550,000

80,000

15

12%

c= r*(NPV)/1-(1+r)-n

R= discount rate

NPV= net persent value

N= length of investment

Machine A:

C= r(NPV)/ 1-(1+r)-n= 12(350,000) / 1-(1+100,000)-10

Machine B:

C= r(NPV)/ 1-(1+r)-n=12(550,000)/ 1(1+80,000)-15

This is all I have so far. I know that I am to figure out the amount of money for the years. I hope you can help.