document.write( "Question 161664: I haven't done a problem like this for several years and I don't remember how to solve it! It's driving me crazy! Here is the problem:\r
\n" ); document.write( "\n" ); document.write( "1024=2^n-1. Solve for n.\r
\n" ); document.write( "\n" ); document.write( "I don't remember how to bring the exponent (n-1) down so that I can solve for n.
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Algebra.Com's Answer #119138 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
There are at least two ways to solve this\r
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\n" ); document.write( "\n" ); document.write( "Method #1:\r
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\n" ); document.write( "\n" ); document.write( "\"1024=2%5E%28n-1%29\" Start with the given equation\r
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\n" ); document.write( "\n" ); document.write( "\"2%5E10=2%5E%28n-1%29\" Rewrite 1,024 as \"2%5E10\". This is possible since \"2%5E10=1024\"\r
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\n" ); document.write( "\n" ); document.write( "Since the bases are equal (they are both 2), this means that the exponents are equal. So \r
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\n" ); document.write( "\n" ); document.write( "\"10=n-1\" Set the exponents equal to one another.\r
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\n" ); document.write( "\n" ); document.write( "\"10%2B1=n%2Bcross%28-1%2B1%29\" Add 1 to both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"11=n\" Add.\r
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\n" ); document.write( "\n" ); document.write( "So the answer is \"n=11\"\r
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\n" ); document.write( "\n" ); document.write( "Method #2\r
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\n" ); document.write( "\n" ); document.write( "\"1024=2%5E%28n-1%29\" Start with the given equation\r
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\n" ); document.write( "\n" ); document.write( "\"log%2810%2C%281024%29%29=log%2810%2C%282%5E%28n-1%29%29%29\" Take the log of both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"log%2810%2C%281024%29%29=%28n-1%29log%2810%2C%282%29%29\" Rewrite the right side using the identity \"log%28b%2C%28x%5Ey%29%29=y%2Alog%28b%2C%28x%29%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"log%2810%2C%281024%29%29%2Flog%2810%2C%282%29%29=n-1\" Divide both sides by \"log%2810%2C%282%29%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"10=n-1\" Evaluate \"log%2810%2C%281024%29%29%2Flog%2810%2C%282%29%29\" to get 10\r
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\n" ); document.write( "\n" ); document.write( "\"10%2B1=n%2Bcross%28-1%2B1%29\" Add 1 to both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"11=n\" Add.\r
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\n" ); document.write( "\n" ); document.write( "So the answer is \"n=11\"
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