document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=188670>Question 188670</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The number of people infected after t days is P = 200 + 5t - t2. Find the number of days until the number of people infected is 150. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #141484 by </B><A HREF=/tutors/aboutme.mpl?userid=nerdybill><B>nerdybill(7384)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=nerdybill><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=nerdybill><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=141484\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> \r<BR>\n" );
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document.write( "P = 200 + 5t - t^2<BR>\n" );
document.write( "The problem gives you:<BR>\n" );
document.write( "P = 150<BR>\n" );
document.write( "150 = 200 + 5t - t^2<BR>\n" );
document.write( "Moving everything to the left:<BR>\n" );
document.write( "t^2 - 5t - 200 + 150 = 0<BR>\n" );
document.write( "t^2 - 5t - 50 = 0<BR>\n" );
document.write( "(t-10)(t+5) = 0<BR>\n" );
document.write( ".<BR>\n" );
document.write( "t = {-5, 10}<BR>\n" );
document.write( "Tossing out the negative solution we are left with:<BR>\n" );
document.write( "t = 10 days<BR>\n" );
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