document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=958685>Question 958685</A>: <I><SPAN STYLE=\"word-break: break-all;\"> what is the solution set to the equation log2(3x+1) + log2(x+7)=5? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #585915 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=585915\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  log2(3x+1) + log2(x+7)=5<BR>\n" );
document.write( " log2(3x+1)(x+7)=5<BR>\n" );
document.write( " (3x+1)(x+7)= 2^5<BR>\n" );
document.write( " 3x^2+21x+x+7= 32<BR>\n" );
document.write( " 3x^2+22x+7= 32<BR>\n" );
document.write( " 3x^2+22x-25= 0<BR>\n" );
document.write( " 3x^2-3x+25x-25= 0<BR>\n" );
document.write( " (3x^2-3x)+(25x-25)= 0<BR>\n" );
document.write( " 3x(x-1)+25(x-1)= 0<BR>\n" );
document.write( " (x-1)(3x+25)= 0<BR>\n" );
document.write( " x = {-25,1}<BR>\n" );
document.write( "throw out the negative solution (extraneous) leaving<BR>\n" );
document.write( " x = 1 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );