document.write( "Question 312331: please help me write the series in summation notation.\r
\n" ); document.write( "\n" ); document.write( "3+12+21+30+39+48+57\r
\n" ); document.write( "\n" ); document.write( "and\r
\n" ); document.write( "\n" ); document.write( "125+50+20+8+....
\n" ); document.write( "

Algebra.Com's Answer #223282 by solver91311(24713)\"\" \"About 
You can put this solution on YOUR website!
\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "John
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" );