document.write( "Question 1059601: Express the sum using summation notation. 15+13+11+...+(-43) \n" ); document.write( "

Algebra.Com's Answer #674789 by Fombitz(32388) $\"\"$ $\"About$

You can put this solution on YOUR website!
First find the term,
\n" ); document.write( " $\"A%5Bn%5D=15%2B%28n-1%29%28-2%29=15-2n=17-2n\"$
\n" ); document.write( "and
\n" ); document.write( " $\"17-2n=-43\"$
\n" ); document.write( " $\"-2n=-60\"$
\n" ); document.write( " $\"n=30\"$
\n" ); document.write( "So,
\n" ); document.write( " $\"S%5B30%5D=sum%28%2817-2i%29%2Cni=1%2C30%29\"$
\n" ); document.write( " \n" ); document.write( "

\n" );