document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=961264>Question 961264</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Explain why 2^x = 15 cannot always be solved in the same way as 2^x = 16. How would you solve each? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #587436 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=587436\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Explain why 2^x = 15 cannot always be solved in the same way as 2^x = 16. How would you solve each?<BR>\n" );
document.write( "------<BR>\n" );
document.write( "16 is a power of 2,<BR>\n" );
document.write( "So 2^x = 2^4<BR>\n" );
document.write( "x = 4<BR>\n" );
document.write( "-----------------<BR>\n" );
document.write( "15 is hard to evaluate as a power of 2<BR>\n" );
document.write( "so 2^x = 15<BR>\n" );
document.write( "x*log(2) = log(15)<BR>\n" );
document.write( "x = log(15)/log(2)<BR>\n" );
document.write( "x = 3.0746<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "--------------------- </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );