document.write( "Question 70330: Solve for x: 3^2x = 12\r
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document.write( "x = ?\r
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document.write( "Round to 2 decimal places. \n" );
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Algebra.Com's Answer #50168 by bucky(2189) ![]() You can put this solution on YOUR website! I interpret your problem to be to solve for x in the equation: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "and I assume you know the use of logarithms and exponents. \n" ); document.write( ". \n" ); document.write( "By using the power rule of exponents you can re-write the equation in the form: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "Take the log of both sides to get: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "But by the rules of exponents in logarithms, the exponent becomes a multiplier of the \n" ); document.write( "log. x is the exponent, so it becomes the multiplier of log(9) to give: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "To solve for x, divide both sides by log(9) to get: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "Calculator time! log(12) = 1.079181246 and log(9) = 0.954242509. By dividing log(12) by \n" ); document.write( "log(9) you find that x = 1.130929754. \n" ); document.write( ". \n" ); document.write( "That's the answer. By doubling it and raising 3 to that exponent on your calculator \n" ); document.write( "you will find that the answer is, as it should be, 12. \n" ); document.write( ". \n" ); document.write( "And don't forget to round the answer to two decimal places as the problem requests. \n" ); document.write( ". \n" ); document.write( "Hope that I interpreted the problem correctly and that the approach I used was not beyond \n" ); document.write( "where you are in your text. \n" ); document.write( " |