document.write( "Question 783381: Please help me solve this qeustion, The second term of a g.p is 6 and the 4th term is 24 find the sum of the first 4 term \n" ); document.write( "
Algebra.Com's Answer #476935 by KMST(5328)\"\" \"About 
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\"b%5B1%5D\" = first term of the geometric progression
\n" ); document.write( "\"r\" = common ratio of the geometric progression
\n" ); document.write( "\"b%5Bn%5D=b%5B1%5D%2Ar%5E%28n-1%29\" = nth term of the geometric progression\r
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\n" ); document.write( " --> --> \"system%28b%5B1%5D%2Ar=6%2Cr=sqrt%284%29=2%29\" --> \"system%28b%5B1%5D%2A2=6%2Cr=2%29\" --> \"system%28b%5B1%5D=6%2F2=3%2Cr=2%29\"
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\n" ); document.write( "\"b%5B3%5D=3%2A2%5E%283-1%29=3%2A2%5E2=3%2A4=12\"
\n" ); document.write( "The sum of the first four terms is
\n" ); document.write( "\"3%2B6%2B12%2B24=highlight%2845%29\"
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\n" ); document.write( "If we wanted to get more complicated we could use a formula for the sum of the first \"n\" terms, \"S%5Bn%5D\".
\n" ); document.write( "\"S%5Bn%5D=b%5B1%5D%2A%28r%5En-1%29%2F%28r-1%29\"
\n" ); document.write( "\"S%5B4%5D=3%2A%282%5E4-1%29%2F%282-1%29=3%2A%2816-1%29%2F1=3%2A15=highlight%2845%29\"
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