document.write( "Question 92161: Find the solution sets for the following:\r
\n" );
document.write( "\n" );
document.write( "In (3x) = 6 \n" );
document.write( "
Algebra.Com's Answer #67006 by bucky(2189)![]() ![]() ![]() You can put this solution on YOUR website! Given: \n" ); document.write( ". \n" ); document.write( "ln (3x) = 6 \n" ); document.write( ". \n" ); document.write( "By the rules of logarithms, the log of a product is equal to the sum of the logs of each \n" ); document.write( "of the terms in the product. Therefore, ln(3*x) = ln(3) + ln(x). Substitute this into the \n" ); document.write( "given equation and it becomes: \n" ); document.write( ". \n" ); document.write( "ln(3) + ln(x) = 6 \n" ); document.write( ". \n" ); document.write( "Subtract ln(3) from both sides to get rid of that term on the left side. After this \n" ); document.write( "subtraction the equation is: \n" ); document.write( ". \n" ); document.write( "ln(x) = 6 - ln(3) \n" ); document.write( ". \n" ); document.write( "But ln(3) is just a number that you can get from a scientific calculator. Enter 3 and then \n" ); document.write( "press the ln key. You will find that ln(3) is equal to 1.098612289. Replace ln(3) in \n" ); document.write( "the equation with that number and you get: \n" ); document.write( ". \n" ); document.write( "ln(x) = 6 - 1.098612289 \n" ); document.write( ". \n" ); document.write( "Perform the subtraction on the right side of the equation and the equation reduces to: \n" ); document.write( ". \n" ); document.write( "ln(x) = 4.901387711 \n" ); document.write( ". \n" ); document.write( "Next convert this logarithmic equation into it equivalent exponential form using the following \n" ); document.write( "rule of logarithms: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "And in this problem the base, b, of the natural logarithms is the number e (which is \n" ); document.write( "2.718281828). \n" ); document.write( ". \n" ); document.write( "So converting to exponential form results in an equation transformation of: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "and since e is approximately 2.718281828 this becomes: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "Using a scientific calculator to raise 2.718281828 to the 4.90138771 power results in \n" ); document.write( "an answer of: \n" ); document.write( ". \n" ); document.write( "x = 134.4762643 \n" ); document.write( ". \n" ); document.write( "You also could have done the problem by beginning with the conversion to exponential \n" ); document.write( "form directly. That is, starting with: \n" ); document.write( ". \n" ); document.write( "ln(3x) = 6 \n" ); document.write( ". \n" ); document.write( "immediately raise the base e to the sixth power and set it equal to 3x as follows: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "Then divide both sides by 3 to find that: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "Then you can raise e to the sixth power \n" ); document.write( "of 403.4287935 which you then divide by 3 to find that x = 134.4762645 \n" ); document.write( ". \n" ); document.write( "The slight difference in the very last decimal place between this answer and the answer we \n" ); document.write( "got using the first method involves just calculator round off in all the steps of the \n" ); document.write( "first method. This second method is a little more accurate because the round off only occurs \n" ); document.write( "in the very last calculation. \n" ); document.write( ". \n" ); document.write( "Hope this helps you to understand the problem a little better. The basis of answering \n" ); document.write( "this problem is knowing how to convert from logarithmic form to exponential form and you \n" ); document.write( "need to memorize that conversion. It gets used a lot in solving logarithmic equations. \n" ); document.write( ". \n" ); document.write( " |