document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=914456>Question 914456</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A jeweler has five rings, each weighing 16 grams, made of an alloy of 10% silver and 90% gold. He decides to melt down the rings and add enough silver to reduce the gold content to 80%.\r<BR>\n" );
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document.write( "(a) Construct a model that gives the fraction G(x) of the new alloy that is pure gold. (Let x represent the number of grams of silver added.) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #555117 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=555117\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 5 rings, 16 grams each ----> 5*16 = 80 grams total\r<BR>\n" );
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document.write( "10% silver: 80*0.10 = 8 grams of pure silver<BR>\n" );
document.write( "90% gold: 80*0.90 = 72 grams of pure gold\r<BR>\n" );
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document.write( "We have 72 grams of pure gold out of 80 grams of alloy (silver + gold)\r<BR>\n" );
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document.write( "Currently, the fraction is 72/80. This leads to 9/10 = 90% gold\r<BR>\n" );
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document.write( "Now add x grams of pure silver. We do NOT add this to the 72 since that represents all gold. We add this to the 80 since that represents silver+gold.\r<BR>\n" );
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document.write( "So we have this fraction now: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=72%2F%2880%2Bx%29 ALIGN=MIDDLE  ALT=\"72%2F%2880%2Bx%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "So the model is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=G%28x%29+=+72%2F%2880%2Bx%29 ALIGN=MIDDLE  ALT=\"G%28x%29+=+72%2F%2880%2Bx%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "We want the gold fraction to be equal to 80/100 (ie 80%), so <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=g%28x%29+=+80%2F100 ALIGN=MIDDLE  ALT=\"g%28x%29+=+80%2F100\"   DISABLED_style= \"max-width:90%; height:auto;\" > and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=72%2F%2880%2Bx%29+=+80%2F100 ALIGN=MIDDLE  ALT=\"72%2F%2880%2Bx%29+=+80%2F100\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Solve for x\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=72%2F%2880%2Bx%29+=+80%2F100 ALIGN=MIDDLE  ALT=\"72%2F%2880%2Bx%29+=+80%2F100\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=72%2F%2880%2Bx%29+=+4%2F5 ALIGN=MIDDLE  ALT=\"72%2F%2880%2Bx%29+=+4%2F5\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=72%2A5+=+4%2880%2Bx%29 ALIGN=MIDDLE  ALT=\"72%2A5+=+4%2880%2Bx%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=360+=+320%2B4x ALIGN=MIDDLE  ALT=\"360+=+320%2B4x\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=360+-+320=4x ALIGN=MIDDLE  ALT=\"360+-+320=4x\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=40=4x ALIGN=MIDDLE  ALT=\"40=4x\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=40%2F4=x ALIGN=MIDDLE  ALT=\"40%2F4=x\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10=x ALIGN=MIDDLE  ALT=\"10=x\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=10 ALIGN=MIDDLE  ALT=\"x=10\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "You need to add <font size=5 color=\"red\">10 grams</font> of pure silver to get an 80% gold alloy.\r<BR>\n" );
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document.write( "Let me know if you need more help or if you need me to explain a step in more detail.<BR>\n" );
document.write( "Feel free to email me at <a  rel=nofollow HREF=\"mailto:jim_thompson5910@hotmail.com?Subject=I%20Need%20Algebra%20Help\">jim_thompson5910@hotmail.com</a><BR>\n" );
document.write( "or you can visit my website here: <a  rel=nofollow HREF=\"http://www.freewebs.com/jimthompson5910/home.html\">http://www.freewebs.com/jimthompson5910/home.html</a>\r<BR>\n" );
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document.write( "Thanks,\r<BR>\n" );
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document.write( "Jim \r<BR>\n" );
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