document.write( "Question 1127671: The first three terms of a G.P are x+1, x+3 and x+8, find,
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Algebra.Com's Answer #744118 by FrankM(1040)\"\" \"About 
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For there to be a common ratio,\r
\n" ); document.write( "\n" ); document.write( "\"%28X%2B8%29%2F%28X%2B3%29+=+%28X%2B3%29%2F%28X%2B1%29\"\r
\n" ); document.write( "\n" ); document.write( "And after cross multiplying -\r
\n" ); document.write( "\n" ); document.write( "X^2+9X+8= X^2+6X+9\r
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\n" ); document.write( "\n" ); document.write( "9X+8=6X+9\r
\n" ); document.write( "\n" ); document.write( "3X=1\r
\n" ); document.write( "\n" ); document.write( "i) X= 1/3 \r
\n" ); document.write( "\n" ); document.write( "ii) Therefore the first 3 numbers are 4/3, 10/3, 25/3 with a common ratio of 2.5\r
\n" ); document.write( "\n" ); document.write( "iii) = A (1+r^n)/(1-r) = 4/3 (1-2.5^15)/(1-2.5)\r
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\n" ); document.write( "\n" ); document.write( "4/3 (-931321.575)/-1.5 = 827841.4\r
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\n" ); document.write( "\n" ); document.write( "I used a spreadsheet to verify the solution is correct. \r
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