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 #821929 by greenestamps(13200)\"\" \"About 
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\n" ); document.write( "The expression is an infinite geometric series with first term a=1 and common ratio r=2x. The sum of an infinite geometric progression is given by the formula

\n" ); document.write( "\"S=a%2F%281-r%29\"

\n" ); document.write( "We are told the sum is 1 1/4 = 5/4:

\n" ); document.write( "\"1%2F%281-2x%29=5%2F4\"

\n" ); document.write( "take reciprocals....

\n" ); document.write( "\"1-2x=4%2F5\"
\n" ); document.write( "\"2x=1-4%2F5=1%2F5\"
\n" ); document.write( "\"x=1%2F10\"

\n" ); document.write( "ANSWER: x=1/10

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