document.write( "Question 936448: Hello,
\n" ); document.write( "We are working on Arithmetic Sequences. I am stuck.
\n" ); document.write( "Can someone please help. I need to find a1 and d.\r
\n" ); document.write( "\n" ); document.write( "a15 = 129, a8=22(a1)\r
\n" ); document.write( "\n" ); document.write( "Thanks. \n" ); document.write( "

Algebra.Com's Answer #569919 by Edwin McCravy(20056) $\"\"$ $\"About$

You can put this solution on YOUR website!

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document.write( "a₁₅ = 129, a₈=22(a1) \r\n" );
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document.write( "   ,   ,   ,   ,   ,   ,   ,  22,   ,   ,   ,   ,   ,   ,129 \r\n" );
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document.write( "Let d be the common difference.  Then since 129 is the 7th term after\r\n" );
document.write( "22, one would have to add the common difference d seven times to get 129,\r\n" );
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document.write( "22+7d=129\r\n" );
document.write( "   7d=107\r\n" );
document.write( "    d=\r\n" );
document.write( "    d=\r\n" );
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document.write( "Now since 22 is the 7th term before the first term we would have to subtract\r\n" );
document.write( "this common difference d seven times to get the first term,  \r\n" );
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document.write( "so the first term =  \r\n" );
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document.write( "First term = -85 and common difference = .\r\n" );
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document.write( "FYI, the whole sequence is:\r\n" );
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document.write( ",,,,,,,,,,,,,,\r\n" );
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document.write( "Edwin

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