document.write( "Question 1190544: Using the Loan Formula P_0= D(1-(1+r/k)^-Nk)` dividing by `(R/k)\r
\n" ); document.write( "\n" ); document.write( "Kyle is considering putting a 1000 laptop purchase on their credit card, which has an interest rate of 24% compounded monthly, how long will it take them to pay off the purchase if they make payments of 30 a month?\r
\n" ); document.write( "\n" ); document.write( "I am just stuck on the second step, if anyone can help thanks!!
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Algebra.Com's Answer #822235 by math_tutor2020(3835)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "N = number of months remaining
\n" ); document.write( "P = loan balance when N months remain
\n" ); document.write( "D = 30 = monthly payment
\n" ); document.write( "r = 0.24 = decimal form of the 24% interest rate
\n" ); document.write( "k = 12 = number of payments per year (aka monthly)\r
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\n" ); document.write( "\n" ); document.write( "r/k = 0.24/12 = 0.02\r
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\n" ); document.write( "\n" ); document.write( "If we plugged in P = 1000 and solved for N, we would find the month number when the balance is $1000
\n" ); document.write( "In other words, it would tell us how long the loan is.\r
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\n" ); document.write( "\n" ); document.write( "\"P+=+D%281-%281%2Br%2Fk%29%5E%28-N%29%29%2F%28r%2Fk%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"1000+=+30%281-%281%2B0.02%29%5E%28-N%29%29%2F%280.02%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"1000%2A0.02+=+30%281-%281.02%29%5E%28-N%29%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"20+=+30%281-%281.02%29%5E%28-N%29%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"20%2F30+=+1-%281.02%29%5E%28-N%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"2%2F3+=+1-%281.02%29%5E%28-N%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"1-%281.02%29%5E%28-N%29+=+2%2F3\"\r
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\n" ); document.write( "\n" ); document.write( "\"-%281.02%29%5E%28-N%29+=+2%2F3-1\"\r
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\n" ); document.write( "\n" ); document.write( "\"-%281.02%29%5E%28-N%29+=+-1%2F3\"\r
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\n" ); document.write( "\n" ); document.write( "\"%281.02%29%5E%28-N%29+=+1%2F3\"\r
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\n" ); document.write( "\n" ); document.write( "\"log%28%28%281.02%29%5E%28-N%29%29%29+=+log%28%281%2F3%29%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"-N%2Alog%28%281.02%29%29+=+log%28%281%2F3%29%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"N+=+-log%28%281%2F3%29%29%2Flog%28%281.02%29%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"N+=+55.4781076387803\"\r
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\n" ); document.write( "\n" ); document.write( "That rounds up N = 56\r
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\n" ); document.write( "\n" ); document.write( "Note what happens when N = 55
\n" ); document.write( "\"P+=+D%281-%281%2Br%2Fk%29%5E%28-N%29%29%2F%28r%2Fk%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"P+=+30%281-%281%2B0.02%29%5E%28-55%29%29%2F%280.02%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"P+=+995.24362567013\"
\n" ); document.write( "which is a bit short of $1,000\r
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\n" ); document.write( "\n" ); document.write( "If we tried N = 56, then,
\n" ); document.write( "\"P+=+D%281-%281%2Br%2Fk%29%5E%28-N%29%29%2F%28r%2Fk%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"P+=+30%281-%281%2B0.02%29%5E%28-56%29%29%2F%280.02%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"P+=+1005.14080948052\"
\n" ); document.write( "which is a bit over the target. So this confirms that N is somewhere between 55 and 56
\n" ); document.write( "We round N up to the nearest whole number so that we guarantee to make the final monthly payment.\r
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\n" ); document.write( "\n" ); document.write( "This is a handy calculator to check your work.
\n" ); document.write( "https://www.calculator.net/credit-card-calculator.html
\n" ); document.write( "Type $1000 for the balance, 24% for the rate, and $30 for the min payment. Click the \"minimum payment\" radio button and click \"calculate\".
\n" ); document.write( "The calculator should say \"It will take 4 years and 8 months to payoff the balance\"
\n" ); document.write( "This is equivalent to 56 months because 12*4+8 = 48+8 = 56.\r
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\n" ); document.write( "\n" ); document.write( "Answer: 56 months
\n" ); document.write( "This is equivalent to 4 years, 8 months
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