document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=628073>Question 628073</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Twin brothers, person A and person B, can mow their grandparents lawn together in 42 minutes.  Person B takes 13 minutes more than person A.  How long does it take each person to mow alone? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #395356 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=395356\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Twin brothers, person A and person B, can mow their grandparents lawn together in 42 minutes.<BR>\n" );
document.write( " Person B takes 13 minutes more than person A.<BR>\n" );
document.write( " How long does it take each person to mow alone?<BR>\n" );
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document.write( "let t = time required by A to mow it alone<BR>\n" );
document.write( "then<BR>\n" );
document.write( "(t+13) = time required by B<BR>\n" );
document.write( "Let the completed job = 1 (a mowed lawn)<BR>\n" );
document.write( ":<BR>\n" );
document.write( "A shared work equation<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=42%2Fx ALIGN=MIDDLE  ALT=\"42%2Fx\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=42%2F%28%28x%2B13%29%29 ALIGN=MIDDLE  ALT=\"42%2F%28%28x%2B13%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 1<BR>\n" );
document.write( "multiply by x(x+13), resulting in eliminating the denominators,<BR>\n" );
document.write( "42(x+13) + 42x = x(x+13)<BR>\n" );
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document.write( "42x + 546 + 42x = x^2 + 13x<BR>\n" );
document.write( "84x + 546 = x^2 + 13x<BR>\n" );
document.write( "0 = x^2 + 13x - 84x - 546 <BR>\n" );
document.write( "A quadratic equation<BR>\n" );
document.write( "x^2 - 71x - 546 = 0 <BR>\n" );
document.write( "You can use the quadratic formula here, but this will factor<BR>\n" );
document.write( "(x+7)(x-78) = 0<BR>\n" );
document.write( "the positive solution<BR>\n" );
document.write( "x = 78 minutes, A alone<BR>\n" );
document.write( "then<BR>\n" );
document.write( "78+13 = 91 min. B alone<BR>\n" );
document.write( ":<BR>\n" );
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document.write( "See if that works out<BR>\n" );
document.write( "on a calc:<BR>\n" );
document.write( "42/78 + 42/91 = 1 </SPAN>\n" );
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