document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1086562>Question 1086562</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find all real solutions:<BR>\n" );
document.write( "4^x-5(2^x)-24=0 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #700792 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=700792\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 4^x-5(2^x)-24=0<BR>\n" );
document.write( "-------<BR>\n" );
document.write( "2^(2x) - 5*2^x - 24 = 0<BR>\n" );
document.write( "--<BR>\n" );
document.write( "Sub u for 2^x<BR>\n" );
document.write( "u^2 - 5u - 24 = 0<BR>\n" );
document.write( "(u-8)*(u+3) = 0<BR>\n" );
document.write( "u = -3<BR>\n" );
document.write( "2^x = -3  Not allowed<BR>\n" );
document.write( "----------<BR>\n" );
document.write( "u = 8<BR>\n" );
document.write( "2^x = 8<BR>\n" );
document.write( "x = 3<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );