document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=47482>Question 47482</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The height, in feet, of a rocket t secods after blast-off is given by a formula h=1260t-16t^2. After how many seconds will the rocket first reach a height of 23,400 feet? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #31446 by </B><A HREF=/tutors/aboutme.mpl?userid=checkley71><B>checkley71(8403)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=checkley71><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=31446\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 23,400=1260t-16t~2 or 16t~2-1260t+23,400=0 or (t-30)(t-48.75)=0 then\r<BR>\n" );
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document.write( "t=30 & t=4875 correct answe is 30 seconds.\r<BR>\n" );
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document.write( "proof 23,400=1260*30-16(30*30) or 23,400=37,800-16*900 or <BR>\n" );
document.write( "23,400=37,800-14,400 or 23,400=23,400  </SPAN>\n" );
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