## anonymous one year ago Help?? Darby bought a house for $445,000. She financed$356,175 of the purchase price with a 25-year, fixed-rate mortgage with a 7.15% interest rate. What is the total cost of the principal and interest after 25 years? a. $765,468.00 b.$956,364.00 c. $774,442.25 d.$967,577.25

1. amistre64

total sum of the payments of course. how much is a monthly payment?

2. anonymous

Is there a formula that goes with this?

3. amistre64

4. amistre64

payment formula ...

5. anonymous

Would it be P = r(PV)/1-(1+r)^-n?

6. anonymous

Thanks. Hope im right. :)

7. amistre64

it not D, and your formula looks correct

8. amistre64

I never use that form tho, ive never liked it my form goes like this: $Bk^n\frac{k^n-1}{k-1}=P$ we have our loan amount as B our compounding setup is k and n is the number of compounding periods

9. amistre64

356175k^(25*12)(k-1)/(k^(25*12)-1), k=1+.0715/12 http://www.wolframalpha.com/input/?i=356175k%5E%2825*12%29%28k-1%29%2F%28k%5E%2825*12%29-1%29%2C+k%3D1%2B.0715%2F12 then we simply add up all the payments made of 25 years

10. amistre64

If you take any random answer from a spammer, your bound to 'not get it right'

11. anonymous

Ok thanks! So I just take \$2551.56 and multiply it by 25? Sorry, I really suck at math...

12. anonymous

@amistre64

13. anonymous

Wait. Thats not one of my answer choices... That was probably wrong, huh?

14. amistre64

25 years of payments, 12 a year 25*12*P should get us where we need to be

15. amistre64

it was almost right lolo

16. anonymous

Oh! Its A! Right?

17. amistre64

765... yeah, thats what my calcs get me

18. anonymous

Yay! Thank you!!!

19. amistre64

good luck