document.write( "Question 161914: A jumbo chocolate bar with a rectangular shape measures 12 centimeters in length, 7 centimeters in width, and 3 centimeters in thickness. Due to escalating costs of cocoa, management decides to reduce the volume of the bar by 20%. To accomplish this reduction, management decides that the new bar should have the same 3 centimeters thickness, but the length and width of each should be reduced an equal number of centimeters. What should be the dimensions of the new candy bar? \n" ); document.write( "
Algebra.Com's Answer #119433 by ankor@dixie-net.com(22740)\"\" \"About 
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A jumbo chocolate bar with a rectangular shape measures 12 centimeters in length, 7 centimeters in width, and 3 centimeters in thickness. Due to escalating costs of cocoa, management decides to reduce the volume of the bar by 20%. To accomplish this reduction, management decides that the new bar should have the same 3 centimeters thickness, but the length and width of each should be reduced an equal number of centimeters. What should be the dimensions of the new candy bar?
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\n" ); document.write( "Find the original volume of the bar
\n" ); document.write( "12 * 7 * 3 = 252 cu/cm
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\n" ); document.write( "Reduced volume bar
\n" ); document.write( ".8 * 252 = 201.6 cu/cm; (reduced by 20%)
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\n" ); document.write( "Let x = no. of cm that length and width will be reduced
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\n" ); document.write( "(12-x) * (7-x) * 3 = 201.6
\n" ); document.write( "FOIL
\n" ); document.write( "(84 - 12x - 7x + x^2) * 3 = 201.6
\n" ); document.write( ":
\n" ); document.write( "3(x^2 - 19x + 84) = 201.6
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\n" ); document.write( "3x^2 - 57x + 252 - 201.6 = 0
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\n" ); document.write( "3x^2 - 57x + 50.4 = 0
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\n" ); document.write( "Use the quadratic formula to find x:
\n" ); document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"
\n" ); document.write( "In this equation: a=3; b=-57; c=50.5
\n" ); document.write( "\"x+=+%28-%28-57%29+%2B-+sqrt%28-57%5E2+-+4%2A3%2A50.4+%29%29%2F%282%2A3%29+\"
\n" ); document.write( ":
\n" ); document.write( "\"x+=+%2857+%2B-+sqrt%283249+-+604.8+%29%29%2F%286%29+\"
\n" ); document.write( "Do the math here and you will get two solutions, but the one that makes sense:
\n" ); document.write( "x = .9297 cm
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\n" ); document.write( "Reduce the length and width by this amt
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\n" ); document.write( "12-.9297 = 11.0703 cm is the new length
\n" ); document.write( "7 -.9297 = 6.0703 cm is the new width
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\n" ); document.write( "Check solution by finding the volume of the the new bar
\n" ); document.write( "11.0703 * 6.0703 * 3 = 201.6, the required volume\r
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