mariomintchev Group Title I need help with this INTEREST question one year ago one year ago

1. mariomintchev Group Title

2. mariomintchev Group Title

Here's the annuity formula: A=R*( (1+i)^n - 1 ) / (i)

3. mariomintchev Group Title

@jhonyy9 @jim_thompson5910 @karatechopper @Mertsj @TuringTest @UnkleRhaukus

4. mariomintchev Group Title

im confused about what im supposed to do

5. Best_Mathematician Group Title

not everyone have ms office

6. mariomintchev Group Title

@saifoo.khan @luis

7. satellite73 Group Title

isn't this just a multiplication problem?

8. satellite73 Group Title

$644.30\times 12\times 25$ is the total you pay

9. mariomintchev Group Title

i dont know ive been trying to figure it out. i did try multiplying the payments by the years but that wasnt right.

10. satellite73 Group Title

you pay monthly

11. mariomintchev Group Title

ok that's right. i was multiplying bu just the years instead of years times frequency of payments

12. satellite73 Group Title

ok good

13. mariomintchev Group Title

why isnt the 2nd blank 155811.6?

14. satellite73 Group Title

dunno i didn't compute

15. mariomintchev Group Title

nevermind!

16. satellite73 Group Title

$644.30\times 12\times 25-865.62\times 12\times 25$

17. satellite73 Group Title

no that is wrong

18. mariomintchev Group Title

it wanted me to get that answer and then subtract it from the previous to get the difference

19. satellite73 Group Title

$644.30\times 12\times 25-865.62\times 12\times 15$

20. mariomintchev Group Title

yup

21. mariomintchev Group Title

22. mariomintchev Group Title

can you help with this one too please?

23. satellite73 Group Title

i would if i could, but i have absolutely no idea

24. satellite73 Group Title

there is some formula for this that you derive by summing a geometric series, but i don't know it. maybe it is in your book?

25. mariomintchev Group Title

dont have the book. lol i have the annuity formula along with the compounding interest and simple interest formulas

26. satellite73 Group Title

i guess this requires the annuity formula, because you are investing every month (or year)

27. mariomintchev Group Title

yeah thats what i used... i dont really understand the 2nd half of the question though....

28. mariomintchev Group Title

the invest up to 2,900 part

29. satellite73 Group Title

use the formula for yearly at 2,900 per year

30. satellite73 Group Title

i don't know it, so i can't do it

31. mariomintchev Group Title

or maybe i use the compound formula: A=P(1+ r/n)^nt