document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=908183>Question 908183</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Working together, Brian and Collin can solve a hard math problem in 15 minutes. On Monday, Collin worked alone and on Tuesday, Brian worked alone. If it took Brian 6 more minutes to solve the hard problems alone than Collin took, how long did it take Brian and Collin to solve them individually?&#8203;<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #550901 by </B><A HREF=/tutors/aboutme.mpl?userid=richwmiller><B>richwmiller(17219)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=richwmiller><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/cgi-bin/show-face.mpl?user=richwmiller><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=550901\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 1/x+1/(x+6)=1/15<BR>\n" );
document.write( "(15*x*(x+6))/x+(15*x*(x+6))/(x+6)=(15*x*(x+6))/15<BR>\n" );
document.write( "(15*(x+6))+15*x=x*(x+6)<BR>\n" );
document.write( "15*x+90+15*x=x^2+6*x<BR>\n" );
document.write( "30*x+90=x^2+6*x<BR>\n" );
document.write( "x^2-24*x-90=0<BR>\n" );
document.write( "Can it be factored?<BR>\n" );
document.write( "What factors of -90 add up to -24?\r<BR>\n" );
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document.write( "Nevertheless, we will complete the square<BR>\n" );
document.write( "x^2-24*x=90<BR>\n" );
document.write( "add it<BR>\n" );
document.write( "x^2-24*x+(-24/2)=90+(-24/2)<BR>\n" );
document.write( "square it<BR>\n" );
document.write( "x^2-24*x+(576/4)=90+(576/4)<BR>\n" );
document.write( "x^2-24*x+(144)=90+(144)<BR>\n" );
document.write( "x^2-24*x+(144)=234<BR>\n" );
document.write( "(x-12)^2=234<BR>\n" );
document.write( "(x-12)^2=234<BR>\n" );
document.write( "we can continue<BR>\n" );
document.write( "x-12=+-15.2970585<BR>\n" );
document.write( "x=12+-15.2970585<BR>\n" );
document.write( "Positive useful answer:<BR>\n" );
document.write( "x=12+15.2970585<BR>\n" );
document.write( "One answer is x=27.2970585<BR>\n" );
document.write( "x+6=6+27.2970585<BR>\n" );
document.write( "x+6=33.2970585<BR>\n" );
document.write( "check<BR>\n" );
document.write( "1/x+1/(x+6)=1/15<BR>\n" );
document.write( "1/27.2970585+1/(27.2970585+6)=1/15<BR>\n" );
document.write( "1/27.2970585+1/33.2970585=1/15<BR>\n" );
document.write( "0.36633984e-1+0.30032683e-1=0.66666667e-1<BR>\n" );
document.write( "0.66666667e-1=0.66666667e-1<BR>\n" );
document.write( "ok\r<BR>\n" );
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document.write( "Negative useless answer:<BR>\n" );
document.write( "x=12-15.2970585<BR>\n" );
document.write( "Negative answer is x=-3.29705854<BR>\n" );
document.write( "For real life cases involving time, distance and other measurements, we reject the negative results\r<BR>\n" );
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