document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=43458>Question 43458</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0618313850/algebrahomeworkh>college algebra</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> please help with this. I dont understand how to use the formula.\r<BR>\n" );
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document.write( "Use the quadratic formula to solve the equation:\r<BR>\n" );
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document.write( "2x^2 - x - 1= 0\r<BR>\n" );
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document.write( "Thank you </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #28503 by </B><A HREF=/tutors/aboutme.mpl?userid=prabhjyot><B>prabhjyot(165)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=prabhjyot><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=28503\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2x%5E2+-+x+-+1=+0 ALIGN=MIDDLE  ALT=\"2x%5E2+-+x+-+1=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "compare the above equation with standard quadratic equation <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=ax%5E2%2Bbx%2Bc=0 ALIGN=MIDDLE  ALT=\"ax%5E2%2Bbx%2Bc=0\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "we get<BR>\n" );
document.write( "a = 2<BR>\n" );
document.write( "b = -1<BR>\n" );
document.write( "c = -1\r<BR>\n" );
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document.write( "Discriminant: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b%5E2-4ac ALIGN=MIDDLE  ALT=\"b%5E2-4ac\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28-1%29%5E2%2B4%2A2%2A%28-1%29+=+9 ALIGN=MIDDLE  ALT=\"%28-1%29%5E2%2B4%2A2%2A%28-1%29+=+9\"   DISABLED_style= \"max-width:90%; height:auto;\" > \r<BR>\n" );
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document.write( "Discriminant (9) is greater than zero. The equation has two solutions.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F2a ALIGN=MIDDLE  ALT=\"x=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F2a\"   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-%28-1%29%2B-sqrt%28%28-1%29%5E1-4%2A2%2A%28-1%29%29%29%2F%282%2A2%29 ALIGN=MIDDLE  ALT=\"x=%28-%28-1%29%2B-sqrt%28%28-1%29%5E1-4%2A2%2A%28-1%29%29%29%2F%282%2A2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "x1,2 = (1 ± 3) / 2*2<BR>\n" );
document.write( "or\r<BR>\n" );
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document.write( "x1 = 4 / 4 = 1<BR>\n" );
document.write( "x2 = -2 / 4 = -1/2\r<BR>\n" );
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document.write( "or<BR>\n" );
document.write( "x1,2 = 1, -0.5 \r<BR>\n" );
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document.write( "Equation factored: 2(x-1)(x+0.5)<BR>\n" );
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