document.write( "Question 919323: A bracelet that is suppose to be 18k gold weighs 238grams. Gold weighs 19.3 grams per cubic centimeter. Copper weighs 9 grams per cubic centimeter. The volume of the bracelet is 15 cubic centimeters. Is the bracelet really 18k? I know that isn't, I need to set it up in substitution method. \n" ); document.write( "
Algebra.Com's Answer #557771 by ankor@dixie-net.com(22740)\"\" \"About 
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A bracelet that is suppose to be 18k gold weighs 238grams.
\n" ); document.write( " Gold weighs 19.3 grams per cubic centimeter.
\n" ); document.write( " Copper weighs 9 grams per cubic centimeter.
\n" ); document.write( " The volume of the bracelet is 15 cubic centimeters.
\n" ); document.write( " Is the bracelet really 18k?
\n" ); document.write( ":
\n" ); document.write( "pure gold is 24 karat, therefore 18 karat: 18/24 = .75 or 75% gold
\n" ); document.write( ":
\n" ); document.write( "let g = weight of the gold in the bracelet
\n" ); document.write( "let c = weight of copper
\n" ); document.write( ":
\n" ); document.write( "g + c = 15
\n" ); document.write( "c = (15-g)
\n" ); document.write( "and
\n" ); document.write( "19.3g + 9c = 238
\n" ); document.write( "replace c with (15-g)
\n" ); document.write( "19.3g + 9(15-g) = 238
\n" ); document.write( "19.3g + 135 - 9g = 238
\n" ); document.write( "19.3 - 9g = 238 - 135
\n" ); document.write( "10.3g = 103
\n" ); document.write( "g = 103/10.3
\n" ); document.write( "g = 10 grams of gold
\n" ); document.write( "and
\n" ); document.write( "15-10 = 5 grams of copper
\n" ); document.write( ":
\n" ); document.write( "Find the % gold; 10/15 = .667 or 67% gold, not 18k \n" ); document.write( "
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