document.write( "Question 1163713: Cost for copies is a linear function of the number of copies. If 100 copies cost $16.00, and 75 copies cost $13.00, write a formula for copy cost as a linear function of the number of copies. Then find how much it would cost to make 800 copies. \n" ); document.write( "

Algebra.Com's Answer #787891 by ikleyn(52781) $\"\"$ $\"About$

You can put this solution on YOUR website!
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document.write( "It is a standard linear interpolation-extrapolation formula\r\n" );
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document.write( "    y =  + .\r\n" );
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document.write( "With   = 100,   = 16,   = 75,   = 13,  x = 800,  this prediction formula becomes\r\n" );
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document.write( "    y = 16 +  = 16 + 0.12*700 = 100.00  dollars.\r\n" );
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document.write( "When the question is posed as in this post, the person \"should not think\".\r\n" );
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document.write( "He (or she) must know the formula (or use a textbook or handbook or his memory) and follow it literally.\r\n" );
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document.write( "The only thing the user must understand, is who are the \"Xs\" and who are the \"Ys\".\r\n" );
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document.write( "It is also useful to understand that the formula express a straight line, passing through \r\n" );
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document.write( "the points  (,)  and  (,)  in a coordinate plane.\r\n" );
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