document.write( "Question 294448: Two terms of an arithmetic sequence are a8 =76 and a28=96 find a rule for the nth term \n" ); document.write( "

Algebra.Com's Answer #212326 by Fombitz(32388) $\"\"$ $\"About$

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In general,
\n" ); document.write( " $\"an=a1%2Bn%2Ad\"$
\n" ); document.write( "Find a1 and d,
\n" ); document.write( "1. $\"a8=a1%2B8%2Ad=76\"$ \r
\n" ); document.write( "\n" ); document.write( "2. $\"a28=a1%2B28%2Ad=96\"$
\n" ); document.write( "From eq. 1,
\n" ); document.write( " $\"a1=76-8%2Ad\"$
\n" ); document.write( "Substitute into eq. 2,
\n" ); document.write( " $\"a1%2B28%2Ad=96\"$
\n" ); document.write( " $\"%2876-8%2Ad%29%2B28%2Ad=96\"$
\n" ); document.write( " $\"76%2B20%2Ad=96\"$
\n" ); document.write( " $\"20%2Ad=20\"$
\n" ); document.write( " $\"d=1\"$
\n" ); document.write( "Then from eq. 1,
\n" ); document.write( " $\"a1=76-8%2Ad\"$
\n" ); document.write( " $\"a1=76-8%2A1\"$
\n" ); document.write( " $\"a1=76-8\"$
\n" ); document.write( " $\"a1=68\"$
\n" ); document.write( "So then the rule becomes,
\n" ); document.write( " $\"an=68%2B1%28n%29\"$
\n" ); document.write( " $\"an=68%2Bn\"$
\n" ); document.write( " \n" ); document.write( "

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