document.write( "Question 1051855: Find a and b if \"sum%28+ak%2Bb%2C+k=1%2C+n+%29+=+8n%5E2%2B11n\", given that \"sum%28+k%2C+k=1%2C+n+%29+=+%28n%28n%2B1%29%29%2F2\" \n" ); document.write( "
Algebra.Com's Answer #667319 by Edwin McCravy(20056)\"\" \"About 
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Find a and b if \"sum%28+ak%2Bb%2C+k=1%2C+n+%29+=+8n%5E2%2B11n\", given that \"sum%28+k%2C+k=1%2C+n+%29+=+%28n%28n%2B1%29%29%2F2\"
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document.write( "The easy way is to substitute n=1 and n=2, and not even bother\r\n" );
document.write( "with \"sum%28+k%2C+k=1%2C+n+%29+=+%28n%28n%2B1%29%29%2F2\"\r\n" );
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document.write( "Substituting n=1:\r\n" );
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document.write( "\"sum%28+ak%2Bb%2C+k=1%2C+1+%29+=+a%281%29%2Bb=a%2Bb=8%281%29%5E2%2B11%281%29=8%2B11=19\"\r\n" );
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document.write( "So \"a%2Bb=19\"\r\n" );
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document.write( "Substituting n=2\r\n" );
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document.write( "So \"3a%2B2b=54\"\r\n" );
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document.write( "Solve the system:\r\n" );
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document.write( "\"system%28a%2Bb=19%2C3a%2B2b=54%29\"\r\n" );
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document.write( "by substitution or elimination\r\n" );
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document.write( "Get a=16, b=3 \r\n" );
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document.write( "\"sum%28+16k%2B3%2C+k=1%2C+n+%29+=+8n%5E2%2B11n\"\r\n" );
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document.write( "Edwin
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