document.write( "Question 475976: http://imageshack.us/photo/my-images/824/page679.jpg/
\n" ); document.write( "I need help number 11 Please! \n" ); document.write( "

Algebra.Com's Answer #326431 by Tatiana_Stebko(1539) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"sum%2814-2k%2C+k=3%2C+15%29\"$
\n" ); document.write( "if $\"k=3\"$ $\"a1=14-2%2A3=8\"$
\n" ); document.write( " $\"k=4\"$ $\"a2=14-2%2A4=6\"$
\n" ); document.write( " $\"k=5\"$ $\"a3=14-2%2A5=4\"$
\n" ); document.write( "...
\n" ); document.write( " $\"k=15\"$ $\"a13=14-2%2A15=-16\"$
\n" ); document.write( "8, 6, 4, ... the arithmetic series
\n" ); document.write( " $\"a1=8\"$ , $\"d=-2\"$
\n" ); document.write( "Use formula $\"Sn=%28n%2F2%29%28a1%2Ban%29\"$
\n" ); document.write( " $\"n=13\"$ , $\"a1=8\"$ , $\"a13=-16\"$
\n" ); document.write( " $\"sum%2814-2k%2C+k=3%2C+15%29=S13=%2813%2F2%29%288%2B%28-16%29%29=-52\"$ \n" ); document.write( "

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