document.write( "Question 958597: Given two terms of the arithmetic sequence, a7=12 and a10=-9, find a1 and d. \n" ); document.write( "
Algebra.Com's Answer #585956 by Fombitz(32388)\"\" \"About 
You can put this solution on YOUR website!
\"a%5Bn%5D=a%5B0%5D%2Bn%2Ad\"
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\n" ); document.write( "\"a%5B7%5D=a%5B0%5D%2B7d=12\"
\n" ); document.write( "\"a%5B10%5D=a%5B0%5D%2B10d=-9\"
\n" ); document.write( "Subtracting,
\n" ); document.write( "\"a%5B0%5D%2B10d-a%5B0%5D-7d=-9-12\"
\n" ); document.write( "\"3d=-21\"
\n" ); document.write( "\"d=-7\"
\n" ); document.write( "Then use either value for find \"a%5B0%5D\".
\n" ); document.write( "\"a%5B0%5D%2B7%28-7%29=12\"
\n" ); document.write( "\"a%5B0%5D-49=12\"
\n" ); document.write( "\"a%5B0%5D=61\"
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\n" ); document.write( "\"a%5Bn%5D=61-7d\"\r
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