document.write( "Question 1146418: Please help me evaluate log27 base 3 + log6 base 3 - log54 base 3 \n" ); document.write( "
Algebra.Com's Answer #767667 by Theo(13342) You can put this solution on YOUR website! your problem is:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "log3(27) + log3(6) - log3(54)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the rules of logarithms state that log(a*b/c) = log(a) + log(b) - log(c).\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this rule applies regardless of the base of the logarithm as long as all the bases are the same.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this is the case in your problem.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "also, the logarithms base conversion rule states that loga(x) = logb(x)/logb(a)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "loga(x) means log(x) base a, as you have shown in your statement of the problem.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the log conversion rule is especially useful when using your calculator to find the log of any log to the base other than 10 (log function) or base other than e (ln function).\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "therefore, your problem can be solved as follows.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "log3(27) + log3(6) - log3(54) = log3(27*6/54) = log10(27*6/54)/log10(3) = log(27*6/54)/log(3) using the log function of your calculator.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you could also have used the ln function of your calculator and gotten the same answer as shown below.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you would get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "log(27*6/54)/log(3) = 1\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "ln(27*6/54)/ln(3) = 1\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you could also have converted to base 10 before anything else as shown below:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "log3(27) + log3(6) - log3(54) = log(27)/log(3) + log(6)/log(3) - log54)/log(3) = (log(27) + log(6) - log(54)) / log(3).\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "at this point, you could have just used your calculator to get (log(27) + log(6) - log(54)) / log(3) = 1, or you could have converted using the rules of logarithms to get log(27 * 6 / 54) / log(3) = 1.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "using log function without specifying the base implies log10. \n" ); document.write( "this is the default for all calculator log functions that i know of.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |