document.write( "Question 1190304: Please help me solve this math problem:If the sum of 1+2x+4x²+8x³+... 1¼. Find x \n" ); document.write( "

Algebra.Com's Answer #821918 by ikleyn(52794) $\"\"$ $\"About$

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\n" ); document.write( "Please help me solve this math problem: If the sum of 1 + 2x + 4x² + 8x³ +... 1¼. Find x
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\n" ); document.write( "\n" ); document.write( "In your post, the equality sign was missed, making the problem non-sensical.\r
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\n" ); document.write( "\n" ); document.write( "So, I restored this missed sign, and now the problem looks like\r
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document.write( "    If the sum of 1 + 2x + 4x² + 8x³ + . . . = 1¼, find x.\r\n" );
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\n" ); document.write( "\n" ); document.write( " Solution\r
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document.write( "The left side is the sum of the infinite geometric progression.\r\n" );
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document.write( "The first term of this progression is  a= 1;  the common ratio is r = 2x.\r\n" );
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document.write( "Such progression has the sum  .  In your case, it leads to equation\r\n" );
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document.write( "     = .\r\n" );
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document.write( "From the equation\r\n" );
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document.write( "    5*(1-2x) = 4\r\n" );
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document.write( "    5 - 10x = 4\r\n" );
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document.write( "    5 - 4 = 10x\r\n" );
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document.write( "      1   = 10x\r\n" );
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document.write( "      x =  = 0.1.    ANSWER\r\n" );
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\n" ); document.write( "\n" ); document.write( "Solved.\r
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