document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1018734>Question 1018734</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In April, Bob changed 1140 Indian Rupees into German Marks when the rate of exchange was x Rupees = 1 Mark. In August, he again changed 1140 Rupees into Marks. The rate of exchange was then (x+1) Rupees = 1 Mark. He received 3 Marks less in April than he did in August. Solve the equation: x^2 + x - 380 = 0 to find the rate of exchange in April.\r<BR>\n" );
document.write( "\n" );
document.write( "How? I understand the equation and everything else, but I am just stuck on the last bit of the question. How do you do this? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #634816 by </B><A HREF=/tutors/aboutme.mpl?userid=josmiceli><B>josmiceli(19441)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josmiceli><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=josmiceli><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=634816\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> In April, Bob will receive Marks according to:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+1140%2A%28+1%2Fx+%29+ ALIGN=MIDDLE  ALT=\"+1140%2A%28+1%2Fx+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "In August, he received Marks according to:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+1140%2A%28+1%2F%28x%2B1%29%29+ ALIGN=MIDDLE  ALT=\"+1140%2A%28+1%2F%28x%2B1%29%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "--------------------<BR>\n" );
document.write( "He received 3 Marks less in April than he did in August.<BR>\n" );
document.write( "---------------------<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+1140%2A%28+1%2Fx+%29+=+1140%2A%28+1%2F%28x%2B1%29%29+-+3+ ALIGN=MIDDLE  ALT=\"+1140%2A%28+1%2Fx+%29+=+1140%2A%28+1%2F%28x%2B1%29%29+-+3+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Multiply both sides by <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x%2A%28+x%2B1+%29+ ALIGN=MIDDLE  ALT=\"+x%2A%28+x%2B1+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+1140%2A%28+x%2B1+%29+=+1140x+-+3%2Ax%2A%28+x%2B1+%29+ ALIGN=MIDDLE  ALT=\"+1140%2A%28+x%2B1+%29+=+1140x+-+3%2Ax%2A%28+x%2B1+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+1140x+%2B+1140+=+1140x+-+3x%5E2+-+3x+ ALIGN=MIDDLE  ALT=\"+1140x+%2B+1140+=+1140x+-+3x%5E2+-+3x+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+1140+=+-3x%5E2+-+3x+ ALIGN=MIDDLE  ALT=\"+1140+=+-3x%5E2+-+3x+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x%5E2+%2B+x+%2B+380+=+0+ ALIGN=MIDDLE  ALT=\"+x%5E2+%2B+x+%2B+380+=+0+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "I get a different equation ( sign of 380 )<BR>\n" );
document.write( "I'll use the one they gave:<BR>\n" );
document.write( "----------------------------------<BR>\n" );
document.write( "Use quadratic formula<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x+=+%28-b+%2B-+sqrt%28+b%5E2+-+4%2Aa%2Ac+%29%29+%2F+%282%2Aa%29+ ALIGN=MIDDLE  ALT=\"+x+=+%28-b+%2B-+sqrt%28+b%5E2+-+4%2Aa%2Ac+%29%29+%2F+%282%2Aa%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" >  <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+a+=+1+ ALIGN=MIDDLE  ALT=\"+a+=+1+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b+=+1+ ALIGN=MIDDLE  ALT=\"+b+=+1+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+c+=+-380+ ALIGN=MIDDLE  ALT=\"+c+=+-380+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-------------<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x+=+%28-1+%2B-+sqrt%28+1%5E2+-+4%2A1%2A%28-380%29+%29%29+%2F+%282%2A1%29+ ALIGN=MIDDLE  ALT=\"+x+=+%28-1+%2B-+sqrt%28+1%5E2+-+4%2A1%2A%28-380%29+%29%29+%2F+%282%2A1%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" >  <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x+=+%28-1+%2B-+sqrt%28+1+-+4%2A1%2A%28-380%29%29%29+%2F+%282%2A1%29+ ALIGN=MIDDLE  ALT=\"+x+=+%28-1+%2B-+sqrt%28+1+-+4%2A1%2A%28-380%29%29%29+%2F+%282%2A1%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" >  <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x+=+%28+-1+%2B+sqrt%28+1521+%29%29+%2F+2+ ALIGN=MIDDLE  ALT=\"+x+=+%28+-1+%2B+sqrt%28+1521+%29%29+%2F+2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x+=+%28+-1+%2B+39+%29+%2F+2+ ALIGN=MIDDLE  ALT=\"+x+=+%28+-1+%2B+39+%29+%2F+2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x+=+38%2F2+ ALIGN=MIDDLE  ALT=\"+x+=+38%2F2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x+=+19+ ALIGN=MIDDLE  ALT=\"+x+=+19+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "The rate in April was 19 Rupees = 1 Mark<BR>\n" );
document.write( "-------------<BR>\n" );
document.write( "I looked over my algebra, and I don't see why I<BR>\n" );
document.write( "got a different equation. Their's work and mine doesn't<BR>\n" );
document.write( "Can you see my mistake? </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );