document.write( "Question 760241: The 3rd term of a G.P is 360 and the 6th term is 1215.Find the 1st term and the common ratio \n" ); document.write( "

Algebra.Com's Answer #462509 by KMST(5328) $\"\"$ $\"About$

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DEFINITIONS: $\"b%5B1%5D\"$ = first term, and $\"r\"$ = common ratio
\n" ); document.write( "FORMULAS: $\"b%5Bn%5D=r%2Ab%5Bn-1%5D\"$ and $\"b%5Bn%5D=b%5B1%5D%2Ar%5E%28n-1%29\"$
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\n" ); document.write( "So $\"b%5B3%5D=b%5B1%5D%2Ar%5E2\"$ , and $\"b%5B6%5D=b%5B1%5D%2Ar%5E5\"$ .
\n" ); document.write( "Then $\"b%5B6%5D%2Fb%5B3%5D=b%5B1%5D%2Ar%5E5%2Fb%5B1%5D%2Fr%5E2\"$ --> $\"b%5B6%5D%2Fb%5B3%5D=r%5E5%2Fr%5E2\"$ --> $\"b%5B6%5D%2Fb%5B3%5D=r%5E3\"$
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\n" ); document.write( " $\"system%28b%5B6%5D%2Fb%5B3%5D=r%5E3%2Cb%5B6%5D%2Fb%5B3%5D=%283%2F2%29%5E3%29\"$ --> $\"highlight%28r=3%2F2%29\"$
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\n" ); document.write( " $\"system%28b%5B3%5D=360%2Cb%5B3%5D=b%5B1%5D%2Ar%5E2%2Cr=3%2F2%29\"$ --> $\"360=b%5B1%5D%2A%283%2F2%29%5E2\"$ --> $\"360=b%5B1%5D%2A%289%2F4%29\"$ --> $\"b%5B1%5D=360%2A%284%2F9%29\"$ --> $\"highlight%28b%5B1%5D=160%29\"$ \n" ); document.write( "

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