document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=864482>Question 864482</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A firecracker is fired straight up into the air out of a window of a building. Its height, in meters, is given by h = -5 t^2 + 15 t + 100, where t is the time, in seconds, the fircracker has been in the air. \r<BR>\n" );
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document.write( "By setting up and solving an equation, find the time(s) when it reaches a height of 10 meters </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #521025 by </B><A HREF=/tutors/aboutme.mpl?userid=LinnW><B>LinnW(1048)</B></A><img src=\"/images/stars/stars-12.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=LinnW><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=LinnW><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=521025\">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=h+=+-5+t%5E2+%2B+15t+%2B+100 ALIGN=MIDDLE  ALT=\"h+=+-5+t%5E2+%2B+15t+%2B+100\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Set h = 10<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10+=+-5+t%5E2+%2B+15t+%2B+100 ALIGN=MIDDLE  ALT=\"10+=+-5+t%5E2+%2B+15t+%2B+100\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "add -10 to each side<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0+=+-5+t%5E2+%2B+15t+%2B+90 ALIGN=MIDDLE  ALT=\"0+=+-5+t%5E2+%2B+15t+%2B+90\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "multiply by -1<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=5+t%5E2+-+15t+-+90+=+0 ALIGN=MIDDLE  ALT=\"5+t%5E2+-+15t+-+90+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "divide by 5<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t%5E2+-+3t+-+18+=+0 ALIGN=MIDDLE  ALT=\"t%5E2+-+3t+-+18+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "factor<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28t-6%29%2A%28t%2B3%29=+0 ALIGN=MIDDLE  ALT=\"%28t-6%29%2A%28t%2B3%29=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Possible values for t are 6 and -3<BR>\n" );
document.write( "So the firecracker has been in the air 6 seconds. </SPAN>\n" );
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