document.write( "Question 1016251: Hi,
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document.write( "I'm unsure on how to solve this problem:
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document.write( "Thank you so much to anyone who can help! \n" );
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Algebra.Com's Answer #632684 by Theo(13342)![]() ![]() You can put this solution on YOUR website! 7^(2x) = 49^(3x+1)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "one way to solve this is:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "start with:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "7^(2x) = 49^(3x+1)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "since 49 = 7^2, this equation becomes:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "7^(2x) = (7^2)^(3x+1)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this becomes 7^(2x) = 7^(2*(3x+1)) which becomes:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "7^(2x) = 7^(6x + 2)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "since the base is the same, you can just set the exponents equal to each other and solve for x.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you get 2x = 6x + 2\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "solve for x to get x = -1/2\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "another way to solve it is:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "start with:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "7^(2x) = 49^(3x+1)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "take the log of both sides of the equation to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "log(7^(2x) = log(49^(3x+1))\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this becomes 2x * log(7) = (3x+1) * log(49)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "since 49 is equal to 7^2, this becomes 2x * log(7) = (3x+1) * log(7^2).\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this becomes 2x * log(7) = 2 * (3x + 1) * log(7) which becomes:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "2x * log(7) = (6x + 2) * log(7)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "if you divide both sides of this equation by log(7), you get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "2x = 6x + 2\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "solve for x to get x = -1/2\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "if you did not recognize that 49 = 7^2 and that you could then get 2 * log(7), you could still have solved as follows:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "start with:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "2x * log(7) = (3x+1) * log(49)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "find log(7) and find log(49) and the equation becomes:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "2x * .84509804 = (3x + 1) * 1.69019608\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simplify to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "1.69019608 * x = 3x * 1.69019608 + 1 * 1.69019608\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this becomes 1.69019608 * x = 5.07058824 * x + 1.69019608\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "subtract 1.69019608 * x from both sides of the equation and subtract 1.69019608 from both sides of the equation to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-1.69019608 = 5.07058824 * x - 1.69019608 * x\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "combine like terms to get -1.69019608 = 3.38039216 * x\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "divide both sides of this equation by 3.38039216 and solve for x to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x = 3.38039216 / -1.69019608 = -.5 which is the same as -1/2.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "it was a lot messier because of the arithmetic involved but you go the same answer.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |