document.write( "Question 549482: I am trying to help my niece with an equation. Solving with logarithms, the equation is 5^x=4^(x+3). I cannot remember for the life of me how to solve this..Can you help? \n" ); document.write( "
Algebra.Com's Answer #357784 by lwsshak3(11628)![]() ![]() ![]() You can put this solution on YOUR website! I am trying to help my niece with an equation. Solving with logarithms, the equation is 5^x=4^(x+3). I cannot remember for the life of me how to solve this. \n" ); document.write( "** \n" ); document.write( "using the exponent rule for logs: \n" ); document.write( "xlog5=(x+3)log4 \n" ); document.write( "x/(x+3)=log4/log5 \n" ); document.write( "using calculator \n" ); document.write( "x/(x+3)≈.8614 \n" ); document.write( "x=.8614x+3*.8614 \n" ); document.write( "x-.8614x=2.5841 \n" ); document.write( ".1386x=2.5814 \n" ); document.write( "x=2.5814/.1386=18.6185 \n" ); document.write( "Check: \n" ); document.write( "5^x=5^18.6185=1.0322*10^13 \n" ); document.write( "4^(x+3)=4^(21.6185)=1.0366*10^13 \n" ); document.write( "difference due to rounding errors \n" ); document.write( " |