document.write( "Question 822117: 11. In a geometric sequence the sum of the 2nd and 3rd terms is 12 and the sum of the 3rd and 4th terms is 60. Find the common ratio and the first term. \n" ); document.write( "
Algebra.Com's Answer #494636 by ewatrrr(24785)\"\" \"About 
You can put this solution on YOUR website!
 
\n" );
document.write( "Hi,
\n" );
document.write( "In a geometric sequence the sum of the 2nd and 3rd terms is 12 
\n" );
document.write( "and the sum of the 3rd and 4th terms is 60. 
\n" );
document.write( "Geometric sequence
\n" );
document.write( " \"+a%5Bn%5D+=+a%5B1%5Dr%5E%28n+-+1%29\"
\n" );
document.write( " \"+a%5B2%5D+=+a%5B1%5Dr\"
\n" );
document.write( " \"+a%5B3%5D+=+a%5B1%5Dr%5E%282%29++\"     
\n" );
document.write( " \"+a%5B4%5D+=+a%5B1%5Dr%5E%283%29\"    \"a%5B1%5Dr%5E2%281-r%29+=+60\"        
\n" );
document.write( "Question states***
\n" );
document.write( "\"++a%5B1%5Dr+%2B+a%5B1%5Dr%5E%282%29=+12+\"   0r  \"a%5B1%5Dr%281%2Br%29+=+12\"
\n" );
document.write( "\"++a%5B1%5Dr%5E2+%2B+a%5B1%5Dr%5E%283%29=+60+\" 0r    \"a%5B1%5Dr%5E2%281%2Br%29+=+60\" 
\n" );
document.write( "\"+%2812%2Fr%29r%5E2+=+60\"
\n" );
document.write( "           r = 5   and \"a%5B1%5D+=+12%2F30+=+2%2F5\"
\n" );
document.write( "CHECKING our answer***
\n" );
document.write( "  2 + (2/5)25 = 12 \n" );
document.write( "
\n" );