document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=171386>Question 171386</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A baseball player hits a ball into the air. The ball's height above the ground, in meters, t seconds after being hit, is approximated by h(t)=1+13t-5t^2. Algebraically determine the time when the ball first reaches a height of 9 m. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #126752 by </B><A HREF=/tutors/aboutme.mpl?userid=solver91311><B>solver91311(24713)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=solver91311><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=solver91311><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=126752\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> You want to find the value of t when h(t)=9\r<BR>\n" );
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document.write( "So set the expression for h(t) equal to 9 and solve for t.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2B13t-5t%5E2=9 ALIGN=MIDDLE  ALT=\"1%2B13t-5t%5E2=9\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Put it in standard form:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-5t%5E2%2B13t-8=0 ALIGN=MIDDLE  ALT=\"-5t%5E2%2B13t-8=0\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Factors to <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28x-1%29%28-5x%2B8%29=0 ALIGN=MIDDLE  ALT=\"%28x-1%29%28-5x%2B8%29=0\"   DISABLED_style= \"max-width:90%; height:auto;\" >, so <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=1 ALIGN=MIDDLE  ALT=\"t=1\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=8%2F5 ALIGN=MIDDLE  ALT=\"t=8%2F5\"   DISABLED_style= \"max-width:90%; height:auto;\" >.  But the question asks for when the ball will FIRST be at 9 meters, so pick the lowest time value, namely <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=1 ALIGN=MIDDLE  ALT=\"t=1\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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