document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=47642>Question 47642</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0471151831/algebrahomeworkh></A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> How can I isolate R1?\r<BR>\n" );
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document.write( "1/1.33 = 1/(R1-6) +  1/R1\r<BR>\n" );
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document.write( "This is what I've done:\r<BR>\n" );
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document.write( "1/1.33 =  R1 + (R1-6)<BR>\n" );
document.write( "         -------------<BR>\n" );
document.write( "          (R1-6)(R1)\r<BR>\n" );
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document.write( "1/1.33 = 2R1-6<BR>\n" );
document.write( "         ------<BR>\n" );
document.write( "         (R1-6)(R1)\r<BR>\n" );
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document.write( "I did not know what to do after this. I also tried the following\r<BR>\n" );
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document.write( "1/1.33 =   R1/ (R1-6)(R1) + (R1-6)/(R1-6)(R1)\r<BR>\n" );
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document.write( "1/1.33 =  1/(R1-6) + 1 / R1\r<BR>\n" );
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document.write( "This as far as I've gone\r<BR>\n" );
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document.write( "ISBN 0471-15183-1   CHAPTER 20 PROBLEM 54 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #31514 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=31514\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 1/1.33 = 1/(R1-6) + 1/R1<BR>\n" );
document.write( "I'm going to replace R1 by \"x\" as it is easier to type.<BR>\n" );
document.write( "1/1.33 = 1/(x-6) + 1/x<BR>\n" );
document.write( "1/1.33 = [x+x-6]/[x(x-6)]<BR>\n" );
document.write( "1/1.33 = [2x-6)]/[x^2-6x]<BR>\n" );
document.write( "Cross-multiply to get;<BR>\n" );
document.write( "x^2-6x=2.66x-7.98<BR>\n" );
document.write( "x^2-8.66x+7.98=0\r<BR>\n" );
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document.write( "x=[8.66+sqrt(8.66^2-4(7.98)]/2 or x=[8.66-sqrt(8.66^2-4(7.98)]/2\r<BR>\n" );
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document.write( "x=[8.66+sqrt43.0756]/2 or x=[8.66-sqrt(43.0756)]/2<BR>\n" );
document.write( "Reverting now to x=R1 you get:<BR>\n" );
document.write( "R1=7.61160022... or R1=2.09679956...<BR>\n" );
document.write( " <BR>\n" );
document.write( "Only R1=7.61160022... is a valid answer<BR>\n" );
document.write( "The other is an extraneous result of the way the<BR>\n" );
document.write( "quadratic equation was formed.  That means the <BR>\n" );
document.write( "2nd answer is valid for the quadratic equation but<BR>\n" );
document.write( "not for your original equation.<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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