document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=2172>Question 2172</A>: <I><SPAN STYLE=\"word-break: break-all;\"> please please please what is \r<BR>\n" );
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document.write( "logx81=4 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #861 by </B><A HREF=/tutors/aboutme.mpl?userid=khwang><B>khwang(438)</B></A><img src=\"/images/stars/stars-10.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=khwang><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=861\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Use loga b = 1/logb a,we have<BR>\n" );
document.write( "logx 81= 4 converts to<BR>\n" );
document.write( " 1/log81 x = 4,<BR>\n" );
document.write( " or log81 x = 1/4,<BR>\n" );
document.write( " Hence, x = (81)^1/4 by definition of logarithm.<BR>\n" );
document.write( " So, x = (81)^1/4 = (3^4)^(1/4) = 3^1 = 3.\r<BR>\n" );
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document.write( "  Or use logx 81= log 81/log x = 4, (common logarithm:base 10)<BR>\n" );
document.write( "  So,log x = (log 81)/4, <BR>\n" );
document.write( "  x = 10^((log 81)/4) =  10^((log 3^4)/4) = 10^(4(log 3)/4)<BR>\n" );
document.write( "    = 10^(log 3) = 3\r<BR>\n" );
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document.write( " Kenny<BR>\n" );
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document.write( " </SPAN>\n" );
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