document.write( "Question 278787: log3 (2x – 1) – log3 (x – 4) = 2 \n" ); document.write( "
Algebra.Com's Answer #202797 by Theo(13342)\"\" \"About 
You can put this solution on YOUR website!
your equations reads like this:\r
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\n" ); document.write( "\n" ); document.write( "\"log%283%2C%282x-1%29%29+-+log%283%2C%28x-4%29%29+=+2\"\r
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\n" ); document.write( "\n" ); document.write( "since \"log%28x%2Fy%29+=+log%28x%29+-+log%28y%29\", your equation becomes:\r
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\n" ); document.write( "\n" ); document.write( "\"log%283%2C%28%282x-1%29%2F%28x-4%29%29%29+=+2\"\r
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\n" ); document.write( "\n" ); document.write( "The basic definition of logarithms states that \"y+=+log%28b%2Cx%29\" if and only if \"b%5Ey+=+x\".\r
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\n" ); document.write( "\n" ); document.write( "by the basic definition of logarithms, \"log%283%2C%28%282x-1%29%2F%28x-4%29%29%29+=+2\" if and only if \"3%5E2+=+%282x-1%29%2F%28x-4%29\"\r
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\n" ); document.write( "\n" ); document.write( "simplify to get:\r
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\n" ); document.write( "\n" ); document.write( "9 = (2x-1)/(x-4)\r
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\n" ); document.write( "\n" ); document.write( "multiply both sides of this equation by (x-4) to get:\r
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\n" ); document.write( "\n" ); document.write( "9*(x-4) = (2x-1)\r
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\n" ); document.write( "\n" ); document.write( "simplify to get:\r
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\n" ); document.write( "\n" ); document.write( "9x - 36 = 2x - 1\r
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\n" ); document.write( "\n" ); document.write( "subtract 2x from both sides of this equation and add 36 to both sides of this equation to get:\r
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\n" ); document.write( "\n" ); document.write( "9x - 2x = -1 + 36\r
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\n" ); document.write( "\n" ); document.write( "simplify to get:\r
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\n" ); document.write( "\n" ); document.write( "7x = 35\r
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\n" ); document.write( "\n" ); document.write( "divide both sides of this equation by 7 to get:\r
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\n" ); document.write( "\n" ); document.write( "x = 5\r
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\n" ); document.write( "\n" ); document.write( "your answer should be x = 5.\r
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\n" ); document.write( "\n" ); document.write( "substitute in your original equation to see if this is true.\r
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\n" ); document.write( "\n" ); document.write( "your original equation is:\r
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\n" ); document.write( "\n" ); document.write( "\"log%283%2C%282x-1%29%29+-+log%283%2C%28x-4%29%29+=+2\"\r
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\n" ); document.write( "\n" ); document.write( "substitute 5 for x to get:\r
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\n" ); document.write( "\n" ); document.write( "\"log%283%2C%282%2A5-1%29%29+-+log%283%2C%285-4%29%29+=+2\" which becomes:\r
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\n" ); document.write( "\n" ); document.write( "\"log%283%2C9%29+-+log%283%2C1%29+=+2\" which becomes:\r
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\n" ); document.write( "\n" ); document.write( "\"log%283%2C%289%2F1%29%29+=+2\" which becomes:\r
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\n" ); document.write( "\n" ); document.write( "\"log%283%2C9%29\" = 2 which is true if and only if \"3%5E2+=+9\" which it is.\r
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\n" ); document.write( "\n" ); document.write( "your answer is:\r
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\n" ); document.write( "\n" ); document.write( "x = 5\r
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