document.write( "Question 575118: if you start out with 100 dollars on january and every month there is a 25% deduction of price, on what month will it take you to get a price under 25 dollars, and give an equation of how to find your answer.[remember each month will have a different amount. \n" ); document.write( "

Algebra.Com's Answer #369414 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

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if you start out with 100 dollars on January and every month there is a 25% deduction of price, on what month will it take you to get a price under 25 dollars, and give an equation of how to find your answer
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\n" ); document.write( "let m = month for this to be true
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\n" ); document.write( " $\"100%281-.25%29%5Em\"$ = 25
\n" ); document.write( " $\"100%28.75%5Em%29\"$ = 25
\n" ); document.write( "divide both side by 100
\n" ); document.write( " $\".75%5Em\"$ = $\"25%2F100\"$
\n" ); document.write( " $\".75%5Em\"$ = .25
\n" ); document.write( "use logs here
\n" ); document.write( "m*log(.75) = log(.25)
\n" ); document.write( "m = $\"log%28.25%29%2Flog%28.75%29\"$
\n" ); document.write( "m = 4.82 ~ 5 months; it will less than $25 in May
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\n" ); document.write( "Check on a calc enter: 100 * .75^5 results: $23.73\r
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