document.write( "Question 697075: The population of a town was 10 million on January 1, 2009. The exponential growth function represents the population of the town. If A represents the population of this town t, years after 2009 and P is the original population. In what year will the population first surpass 15 million?\r
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document.write( "My teacher has us first figure out what each letter stands for:\r
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document.write( "15 million A:population of the town
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document.write( "X t: time (years)
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document.write( "10 million p: original population\r
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document.write( "I'm not sure where the numbers go. meaning, does A=15 million, t is what we are solving for, and P is 10 million? They give 10 million as the towns population and ask what year it will surpass to 15 million. would this be the equation:\r
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document.write( "15,000,000=10,000,000\r
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document.write( "if so this is how to solve the word problem, this is how I continued to solve it:\r
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document.write( "15,000,000=10,000,000
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document.write( "5,000,000=\r
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document.write( "then I used Ln and got 5,000,000=0.04t. Then I divided out 0.04 and got 125,000,000. \r
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document.write( "I know this is wrong. I'm pretty sure it is going to be a logarithm question, I'm just not sure how to set up the exponential growth equation with the given numbers.\r
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document.write( "Thank you for your help and for your time. \n" );
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Algebra.Com's Answer #429639 by nerdybill(7384)![]() ![]() You can put this solution on YOUR website! Your equation below is correct: \n" ); document.write( "15,000,000=10,000,000 \n" ); document.write( "dividing each side by 100000: \n" ); document.write( "15=10 \n" ); document.write( "15/10 = \n" ); document.write( "3/2 = \n" ); document.write( "now, you take the \"natural log\" (ln) of both sides to get: \n" ); document.write( "ln(3/2) = 0.04t \n" ); document.write( "ln(3/2)/0.04 = t \n" ); document.write( "10.14 = t \n" ); document.write( "that's 10.14 years after January 1, 2009: \n" ); document.write( "so, that's approximately: \n" ); document.write( "March 1, 2019 \n" ); document.write( " |