document.write( "Question 1119236: the height in cm of a candle is a linear function of the amount of time(hours) its been burning. When graphed, the function gives a line with a slope of -0.6. Suppose the height of the candle after 17 hours is 17.8 cm what was the height of the candle after 10 hours? \n" ); document.write( "

Algebra.Com's Answer #734709 by ikleyn(52802) $\"\"$ $\"About$

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\n" ); document.write( "the height in cm of a candle is a linear function of the amount of time(hours) its been burning.
\n" ); document.write( "When graphed, the function gives a line with a slope of -0.6. Suppose the height of the candle after 17 hours is 17.8 cm
\n" ); document.write( "what was the height of the candle after 10 hours?
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\n" ); document.write( "\n" ); document.write( "            After reading the condition I have a question:   \"10 hours\" after WHAT ?\r
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\n" ); document.write( "\n" ); document.write( "            I will interpret the question in this way:   \"what was the height of the candle after 10 hours from the beginning ?\"\r
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\n" ); document.write( "\n" ); document.write( "1.   The common sense solution\r
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document.write( "The condition says that the candle looses 0.6 cm of its height each hour when it is burning.\r\n" );
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document.write( "After 17 hours the candle was 17.8 cm long.\r\n" );
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document.write( "Hence, after 10 hours from the beginning it was  17.8 + 7*0.6 = 17.8 + 4.2 = 22 cm.\r\n" );
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\n" ); document.write( "\n" ); document.write( "2. The formal solution\r
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document.write( "You have a straight line with the slope of -0.6 passing through the point (x,y) = (17,17.8).\r\n" );
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document.write( "They ask to determine the value of the linear function at  x = 10.\r\n" );
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document.write( "Use the formula   = ,\r\n" );
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document.write( "where m = -0.6 (the slope),   = 10,   = 17.8,   = 10,   = 17.\r\n" );
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document.write( " = 17.8 - 0.6*(10-17) = 17.8 - 0.6*(-7) = 17.8 + 0.6*7 = 22 cm.\r\n" );
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document.write( "You get the same answer as in the solution 1.\r\n" );
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