document.write( "Question 136910: find the sum of the first 10 terms of the series 9+18+36+... \n" ); document.write( "
Algebra.Com's Answer #100202 by dolly(163)\"\" \"About 
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Hi,\r
\n" ); document.write( "\n" ); document.write( "The given series 9 + 18 + 36 +.... is a geometric series whose first term(a) is 9 and the common ratio(r) is 2.\r
\n" ); document.write( "\n" ); document.write( "So sum upto 10 terms = a(1-r^n)/(1-r) where n = 10 here
\n" ); document.write( " = 9(1-2^10)/(1-2)
\n" ); document.write( " = 9(2^10 - 1)/1 [ multiplying by -1 on both numerator and denominator]\r
\n" ); document.write( "\n" ); document.write( " = 9(2^10 -1)
\n" ); document.write( " = 9(1024-1)
\n" ); document.write( " = 9(1023)
\n" ); document.write( " = 9207
\n" ); document.write( "sum upto 10 terms = 9207\r
\n" ); document.write( "\n" ); document.write( "Good luck!!!\r
\n" ); document.write( "\n" ); document.write( "dolly
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