document.write( "Question 1154282: Find the sum of the geometric sequence −3, 15, −75, 375, … when there are 7 terms and select the correct answer below.\r
\n" ); document.write( "\n" ); document.write( "the options are:
\n" ); document.write( "A) -39,063
\n" ); document.write( "B) 39,063
\n" ); document.write( "C) 58,593
\n" ); document.write( "D) -58,593\r
\n" ); document.write( "\n" ); document.write( "if you can, please include a thorough explanation!!! thanks!
\n" ); document.write( "

Algebra.Com's Answer #776679 by MathLover1(20850)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "first we need nth term formula:\r
\n" ); document.write( "\n" ); document.write( "write given terms as follow:\r
\n" ); document.write( "\n" ); document.write( "\"-3=3%2A%28-1%29%5E1%2A5%5E0\"\r
\n" ); document.write( "\n" ); document.write( "\"15=3%2A%28-1%29%5E%282%29%2A5%5E1\"\r
\n" ); document.write( "\n" ); document.write( "\"+-75=3%2A%28-1%29%5E3%2A5%5E2\"\r
\n" ); document.write( "\n" ); document.write( "\"375=3%2A%28-1%29%5E4%2A5%5E3\"
\n" ); document.write( ":
\n" ); document.write( "in general\r
\n" ); document.write( "\n" ); document.write( "\"3+%28-1%29%5En+%2A5%5E%28n+-+1%29\"\r
\n" ); document.write( "\n" ); document.write( "5th term\r
\n" ); document.write( "\n" ); document.write( "\"3+%28-1%29%5E5+%2A5%5E%285+-+1%29=3+%28-1%29%5E5+%2A5%5E4=-1875\"\r
\n" ); document.write( "\n" ); document.write( "6th term\r
\n" ); document.write( "\n" ); document.write( "\"3+%28-1%29%5E6+%2A5%5E%286+-+1%29=3+%28-1%29%5E6+%2A5%5E5=9375\"\r
\n" ); document.write( "\n" ); document.write( "7th term\r
\n" ); document.write( "\n" ); document.write( "\"3+%28-1%29%5E7+%2A5%5E%287+-+1%29=3+%28-1%29%5E7+%2A5%5E6=-46875\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "the sum of the first \"7\" terms geometric sequence is:\r
\n" ); document.write( "\n" ); document.write( "\"+-3%2B+15+-75%2B375-1875%2B9375-46875=-39063\"\r
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\n" ); document.write( "\n" ); document.write( "
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