document.write( "Question 1205016: The sum of the first three terms of a geometric sequence is 8 and the sum of the first six terms is 12.
\n" ); document.write( "Find the common ratio.
\n" ); document.write( "

Algebra.Com's Answer #841618 by Edwin McCravy(20059)\"\" \"About 
You can put this solution on YOUR website!
Thought I'd do it by the sum formula, to see if it's harder or easier.\r\n" );
document.write( "

\n" ); document.write( "The sum of the first three terms of a geometric sequence is 8...
 \r\n" );
document.write( "\"S%5Bn%5D\"\"%22%22=%22%22\"\"%28a%5B1%5D%28r%5En-1%29%29%2F%28r-1%29\"\r\n" );
document.write( "\r\n" );
document.write( "\"S%5B3%5D\"\"%22%22=%22%22\"\"%28a%5B1%5D%28r%5E3-1%29%29%2F%28r-1%29\"\r\n" );
document.write( "\r\n" );
document.write( "\"8\"\"%22%22=%22%22\"\"%28a%5B1%5D%28r%5E3-1%29%29%2F%28r-1%29\"

\n" ); document.write( "and the sum of the first six terms is 12.
\r\n" );
document.write( "\"S%5B6%5D\"\"%22%22=%22%22\"\"%28a%5B1%5D%28r%5E6-1%29%29%2F%28r-1%29\"\r\n" );
document.write( "\r\n" );
document.write( "\"12\"\"%22%22=%22%22\"\"%28a%5B1%5D%28r%5E6-1%29%29%2F%28r-1%29\"\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\"system%288%28r-1%29=a%5B1%5D%28r%5E3-1%29%2C%0D%0A12%28r-1%29=a%5B1%5D%28r%5E6-1%29%29\"\r\n" );
document.write( "\r\n" );
document.write( "Divide the 2nd equation by the first equation:\r\n" );
document.write( "\r\n" );
document.write( "\"12%2F8=%28r%5E6-1%29%2F%28r%5E3-1%29\"\r\n" );
document.write( "\r\n" );
document.write( "\"3%2F2=%28%28r%5E3-1%29%28r%5E3%2B1%29%29%2F%28r%5E3-1%29\"\r\n" );
document.write( "\r\n" );
document.write( "\"3%2F2=%28cross%28%28r%5E3-1%29%29%28r%5E3%2B1%29%29%2Fcross%28r%5E3-1%29\"\r\n" );
document.write( "\r\n" );
document.write( "\"3%2F2=r%5E3%2B1\"\r\n" );
document.write( "\r\n" );
document.write( "\"3=2r%5E3%2B2\"\r\n" );
document.write( "\r\n" );
document.write( "\"1=2r%5E3\"\r\n" );
document.write( "\r\n" );
document.write( "\"1%2F2=r%5E3\"\r\n" );
document.write( "\r\n" );
document.write( "\"root%283%2C1%2F2%29=r\"\r\n" );
document.write( "\r\n" );
document.write( "\"root%283%2Cexpr%281%2F2%29%2Aexpr%282%2F2%29%2Aexpr%282%2F2%29%29=r\"\r\n" );
document.write( "\r\n" );
document.write( "\"root%283%2C4%29%2F2=r\"\r\n" );
document.write( "\r\n" );
document.write( "Edwin
\r
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );