document.write( "Question 720760: 2/log(base x)4 + 3/log(base 4)x = 7 \n" ); document.write( "
Algebra.Com's Answer #441969 by lwsshak3(11628) ![]() You can put this solution on YOUR website! 2/log(base x)4 + 3/log(base 4)x = 7 \n" ); document.write( "convert to Base 10 \n" ); document.write( "2/(log4/logx)+3/(logx/log4)=7 \n" ); document.write( "2logx/log4+3log4/logx=7 \n" ); document.write( "LCD:(logx)(log4) \n" ); document.write( "2(logx)^2+3(log4)^2=7log4logx \n" ); document.write( "log4≈.60206 \n" ); document.write( "2(logx)^2+1.08743=4.21442logx \n" ); document.write( "2(logx)^2-4.21442logx+1.08743=0 \n" ); document.write( "solve for logx using quadratic formula: \n" ); document.write( "logx=.30102 \n" ); document.write( "x=10^.30102 \n" ); document.write( "x≈2 \n" ); document.write( "or \n" ); document.write( "logx=1.80618 \n" ); document.write( "x=10^1.80618 \n" ); document.write( "x≈64 \n" ); document.write( ".. \n" ); document.write( "Check: \n" ); document.write( "for x=2 \n" ); document.write( "2/log(base x)4+3/log(base 4)x \n" ); document.write( "=2/log2(4) + 3/log4(2) \n" ); document.write( "=2/2+3/(1/2) \n" ); document.write( "=1+6=7\r \n" ); document.write( "\n" ); document.write( ".. \n" ); document.write( "for x=64 \n" ); document.write( "2/log(base x)4+3/log(base 4)x \n" ); document.write( "=2/log64(4) + 3/log4(64) \n" ); document.write( "=2/(1/3)+3/3 \n" ); document.write( "=6+1=7 \n" ); document.write( "ans: \n" ); document.write( "x=2 or 64\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |