document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=487026>Question 487026</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A ball thrown into the air reaches a height h (in feet) according to the formula h = -16t2 + 80t, where t is the time elapsed since the ball was thrown. Find the shortest time it will take the ball to reach a height of 64 feet.<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #332917 by </B><A HREF=/tutors/aboutme.mpl?userid=John10><B>John10(297)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=John10><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=John10><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=332917\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> when the height reaches to 64 ft, <BR>\n" );
document.write( "-16t^2 + 80t = 64<BR>\n" );
document.write( "-16t^2 + 80t - 64 = 0<BR>\n" );
document.write( "t^2 - 5t + 4 = 0<BR>\n" );
document.write( "(t - 4) (t - 1) = 0<BR>\n" );
document.write( "t = 4 or t = 1<BR>\n" );
document.write( "thus the shortest time is t = 1 second<BR>\n" );
document.write( "John10:) </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );