document.write( "Question 141415: I am stuck on this linear equation story problem. I was hoping someone could please help me with the formula that I need. \r
\n" ); document.write( "\n" ); document.write( "A magazine subscription service sold 8762 subscriptions in February and 12, 421 subscriptions in May.\r
\n" ); document.write( "\n" ); document.write( "Assuming the number of subscriptions increased at a constant rate, write a linear equation to give the number of subscriptions S in terms of the month m. (Hint: Let the month of January be 1. Set the rest of the month values based on that starting point.)\r
\n" ); document.write( "\n" ); document.write( "I have x= Feb sales y= May sales n = number of months then y-x divided by n should give the rate of change. Am I on the right track?\r
\n" ); document.write( "\n" ); document.write( "This isn't from a book, it is from a problem in one of my online classes. Thanks so much ~Lyn \n" ); document.write( "

Algebra.Com's Answer #103025 by Edwin McCravy(20060) $\"\"$ $\"About$

You can put this solution on YOUR website!
I am stuck on this linear equation story problem. I was hoping someone could please help me with the formula that I need.
\n" ); document.write( "A magazine subscription service sold 8762 subscriptions in February and 12,421 subscriptions in May.
\n" ); document.write( "Assuming the number of subscriptions increased at a constant rate, write a linear equation to give the number of subscriptions S in terms of the month m. (Hint: Let the month of January be 1. Set the rest of the month values based on that starting point.)
\n" ); document.write( "I have x= Feb sales y= May sales n = number of months then y-x divided by n should give the rate of change. Am I on the right track?
\n" ); document.write( "This isn't from a book, it is from a problem in one of my online classes. Thanks so much ~Lyn\r
\n" ); document.write( "\n" ); document.write( "

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document.write( ">>...8762 subscriptions in February...<<\r\n" );
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document.write( "This means\r\n" );
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document.write( "When the month was February, the number of subscriptions was 8762.\r\n" );
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document.write( "which means \r\n" );
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document.write( "When m = 2, S = 8762\r\n" );
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document.write( "which means that one point on the line of the graph is\r\n" );
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document.write( "(m, S) = (2, 8762)\r\n" );
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document.write( "-----\r\n" );
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document.write( ">>...12,421 subscriptions in May...<<\r\n" );
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document.write( "This means\r\n" );
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document.write( "When the month was May, the number of subscriptions was 12,421.\r\n" );
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document.write( "which means \r\n" );
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document.write( "When m = 5, S = 12,421\r\n" );
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document.write( "which means that another point on the line of the graph is\r\n" );
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document.write( "(m, S) = (5, 12421)\r\n" );
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document.write( "The problem now becomes:\r\n" );
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document.write( "Find the equation of the line which passes through the\r\n" );
document.write( "points (2,8762) and (5,12421)\r\n" );
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document.write( "Let's temporarily replace m by x and S by y.\r\n" );
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document.write( "call the two points \r\n" );
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document.write( "(,) = (2,8762), and (,) = (5,12421)\r\n" );
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document.write( "First we find the slope from the formula\r\n" );
document.write( "     \r\n" );
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document.write( "Note that this is a different \"m\" from the \"m\" used in\r\n" );
document.write( "the original problem.  That m stood for month number,\r\n" );
document.write( "but this m stands for the slope.  But that won't cause\r\n" );
document.write( "any difficulty since we will soon have a number for\r\n" );
document.write( "the slope, and won't need m anymore for slope.\r\n" );
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document.write( "Now we use the point slope formula:\r\n" );
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document.write( "Substituting for ,, and \r\n" );
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document.write( "Clear of fractions by multiplying by 3\r\n" );
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document.write( "Distribute on the right\r\n" );
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document.write( "Add 28286 to both sides\r\n" );
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document.write( "Divide thru by 3\r\n" );
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document.write( "Now we only need to change the  to an \r\n" );
document.write( "and the  to an .\r\n" );
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document.write( "Edwin

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