document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1034472>Question 1034472</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Ray threw a ball from the top of a 40 metre building to his sister who was standing below him on a balcony that is 12 m up from the ground. The function h(t)=-2t^2-10t+40 models the height of the ball from the ground, where h(t) is the height in metres and t is the time in seconds. If Ray's throw is accurate, when will his sister catch the ball?<BR>\n" );
document.write( "Show your solution using the factoring method.\r<BR>\n" );
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document.write( "Thanks so much :) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #649121 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=649121\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The ball has to drop 28 meters and h(t) must be 12 feet.<BR>\n" );
document.write( "h(t)=12=-2t^2-10t+40<BR>\n" );
document.write( "-2t^2-10t+28=0<BR>\n" );
document.write( "divide everything by minus 2<BR>\n" );
document.write( "t^2+5t-14=0<BR>\n" );
document.write( "(t+7)(t-2)=0<BR>\n" );
document.write( "positive root only.  t=2 seconds.At that point, h(t)=12.<BR>\n" );
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