document.write( "Question 20558: What is M equal to in: log(3m+7) - log
(m+4) = 2log
6 - 3log
3 I was thinking that you add log
(m+4) to both sides, but i believe that isn't right. \n" );
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Algebra.Com's Answer #10198 by venugopalramana(3286)![]() ![]() You can put this solution on YOUR website! log \n" ); document.write( "use the formula log x to base y =log x/log y where all logs are to any common base. \n" ); document.write( "so we get {(log (3m+7)/log 6)}-{(log (m+4)/log 6)}={(2 log 6/log 6) -(3 log 3/log 6)} \n" ); document.write( "now multiply through out with log 6 to get \n" ); document.write( "log (3m+7)-log (m+4)=2log 6-3log 3 \n" ); document.write( "now use the formula log x^n = n*log x \n" ); document.write( "and log(x/y)=log x-log y \n" ); document.write( "log ((3m+7)/(m+4))=log 6*6-log 3*3*3=log 36-log 27=log(36/27) \n" ); document.write( "taking antilogs on both sides \n" ); document.write( "((3m+7)/(m+4))=36/27=4/3 \n" ); document.write( "cross multiplying \n" ); document.write( "3(3m+7)=4(m+4) \n" ); document.write( "9m+21=4m+16 \n" ); document.write( "9m-4m=16-21=-5 \n" ); document.write( "5m=-5 \n" ); document.write( "m=-1 \n" ); document.write( " \n" ); document.write( " |