document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=605863>Question 605863</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A ball is thrown upward with a velociity of 80ft/s from a height of 576ft.  H= -16t^2+80t=576 gives the height,h, after t sec.  Find the time when the ball is 300ft above the ground.  H value is 300\r<BR>\n" );
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document.write( "OK--I know how that I have to set it to zero by subtracting 300 from 576.  It will not factor out evenly.  After setting it up with the quadratic formula, I am still getting it wrong.  Please help me.  I am on my 5th problem like this and am severly struggleing. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #381844 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=381844\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A ball is thrown upward with a velociity of 80ft/s from a height of 576ft.  H= -16t^2+80t=576 gives the height,h, after t sec.  Find the time when the ball is 300ft above the ground.<BR>\n" );
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document.write( "It's H= -16t^2+80t + 576<BR>\n" );
document.write( "H = 300<BR>\n" );
document.write( "-16t^2+80t + 576 = 300<BR>\n" );
document.write( "-16t^2+80t + 276 = 0<BR>\n" );
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document.write( " <TR><TD  ALIGN=MIDDLE>Solved by <A  rel=nofollow HREF=http://wiki.algebra.com/index.php/Tutoring_-_pluggable_solvers>pluggable</A> solver: <A  rel=nofollow HREF=solve_quadratic_equation.solver>SOLVE quadratic equation (work shown, graph etc)</A></TD></TR>\n" );
document.write( "<TR><TD  ALIGN=LEFT>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;\" > (in our case <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-16x%5E2%2B80x%2B276+=+0 ALIGN=MIDDLE  ALT=\"-16x%5E2%2B80x%2B276+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" >) has the following solutons:<BR>\n" );
document.write( "  <BR>\n" );
document.write( "  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca ALIGN=MIDDLE  ALT=\"x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "  <BR>\n" );
document.write( "  For these solutions to exist, the <U>discriminant</U> <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;\" > should not be a negative number.<BR>\n" );
document.write( "  <BR>\n" );
document.write( "  First, we need to compute the 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=b%5E2-4ac=%2880%29%5E2-4%2A-16%2A276=24064 ALIGN=MIDDLE  ALT=\"b%5E2-4ac=%2880%29%5E2-4%2A-16%2A276=24064\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "  <BR>\n" );
document.write( "  Discriminant d=24064 is greater than zero. That means that there are two solutions: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x%5B12%5D+=+%28-80%2B-sqrt%28+24064+%29%29%2F2%5Ca ALIGN=MIDDLE  ALT=\"+x%5B12%5D+=+%28-80%2B-sqrt%28+24064+%29%29%2F2%5Ca\"   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%5B1%5D+=+%28-%2880%29%2Bsqrt%28+24064+%29%29%2F2%5C-16+=+-2.34767985741633 ALIGN=MIDDLE  ALT=\"x%5B1%5D+=+%28-%2880%29%2Bsqrt%28+24064+%29%29%2F2%5C-16+=+-2.34767985741633\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "    <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5B2%5D+=+%28-%2880%29-sqrt%28+24064+%29%29%2F2%5C-16+=+7.34767985741633 ALIGN=MIDDLE  ALT=\"x%5B2%5D+=+%28-%2880%29-sqrt%28+24064+%29%29%2F2%5C-16+=+7.34767985741633\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "    <BR>\n" );
document.write( "    Quadratic expression <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-16x%5E2%2B80x%2B276 ALIGN=MIDDLE  ALT=\"-16x%5E2%2B80x%2B276\"   DISABLED_style= \"max-width:90%; height:auto;\" > can be factored:<BR>\n" );
document.write( "  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-16x%5E2%2B80x%2B276+=+%28x--2.34767985741633%29%2A%28x-7.34767985741633%29 ALIGN=MIDDLE  ALT=\"-16x%5E2%2B80x%2B276+=+%28x--2.34767985741633%29%2A%28x-7.34767985741633%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "  Again, the answer is: -2.34767985741633, 7.34767985741633.\n" );
document.write( "Here's your graph:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+-16%2Ax%5E2%2B80%2Ax%2B276+%29 ALIGN=MIDDLE  ALT=\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+-16%2Ax%5E2%2B80%2Ax%2B276+%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ></TD></TR>\n" );
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document.write( "t =~ 7.348 seconds<BR>\n" );
document.write( "Ignore the negative time.<BR>\n" );
document.write( "Ignore the \"It can be factored.\" statement, too.<BR>\n" );
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