I have no idea how to do this...

Help determine the best deal.

Balance After ( T= time year)
Credit Card Equation 0 year 3months 6months 1year 2years
A $607.99(1.15)^12t $607.99 $664.80
B $607.99 (1.09) ^2t
C $607.99 (1.0425) ^4t

6 answers

This might help
https://www.vcalc.com/wiki/KurtHeckman/Credit+Card+Equation
Didn't really help :(
Sorry, here is perhaps a better source. I do not really know what you are asking so am trying to find explanations of credit card calculations. I assume you are trying to find the card that has the least total interest expense for a given payback period.
http://calculatecreditcard.com/how-credit-card-interest-is-calculated/
well this is the rest of the question

Tyler has just graduated high school and has some credit card offers! The first credit card (Credit Card A) charges 18% compounded monthly. The second credit card (Credit Card B) charges 18% compounded semi-annually. The third credit card (Credit Card C) charges 17% compounded quarterly.

Think about it: Which credit card do you assume will be the best deal?
Tyler isn’t sure which credit card is the best deal, so he wants to do some comparison. You’re going to help him out using the skills you learned in the Exponents Unit to create some equations and graphs to determine the best deal.

Let’s suppose he is going to buy a smartphone for $607.99 and put the entire balance on the credit card. (2pts each)

Credit card A
B=607.99(1.15) ^12t

Credit card B
B=607.99 (1.09) ^2t

Credit card C
B=607.99 (1.0425) ^4t
and then I did this so far
Help determine the best deal.

Balance After ( T= time year)
Credit Card Equation 0 year 3months 6months 1year 2years
A $607.99(1.15)^12t $607.99 $664.80
B $607.99 (1.09) ^2t
C $607.99 (1.0425) ^4t
Credit card A
B=607.99(1.15) ^12t
======================== no 18/12 = 1.5
1.5/100 = .015 NOT .15
so it is 1 .015^12 = 1.1956

18/2 = 9 so 1.09^2 = 1.188 LESS !

17/4 = 4.25 so 1.0425^4 = 1.181 LEAST !!!