document.write( "Question 696868: hi i'm confused about this question it asks the third term of an arithmitic sequence is 4 and the sum of the first 8 term is 36. write down the first 8 terms of the sequence. \n" ); document.write( "

Algebra.Com's Answer #429410 by abhishek meena(6) $\"\"$ $\"About$

You can put this solution on YOUR website!
a(3)=4
\n" ); document.write( "s(8)=36
\n" ); document.write( "s(n)=(n/2)(2a+(n-1)d)
\n" ); document.write( "here n=8
\n" ); document.write( "therefore, s(8)=4(2a+7d)=8a+28d=36 - first equation
\n" ); document.write( "also a(n)=a+(n-1)d
\n" ); document.write( "therefore a(3)=a+2d=4 - second equation\r
\n" ); document.write( "\n" ); document.write( "now solve both equation\r
\n" ); document.write( "\n" ); document.write( "8(4-2d)+28d=36
\n" ); document.write( "32-16d+28d=36
\n" ); document.write( "32+12d=36
\n" ); document.write( "12d=4
\n" ); document.write( "d=1/3\r
\n" ); document.write( "\n" ); document.write( "therefore a=4-2d=4-2(1/3)=10/3\r
\n" ); document.write( "\n" ); document.write( "now using formula for terms i.e. a(n)=a+(n-1)d\r
\n" ); document.write( "\n" ); document.write( "10/3, 11/3, 4, 13/3, 14/3, 5 ,16/3 , 17/3\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "solved....cheers\r
\n" ); document.write( "\n" ); document.write( "my method is easier than mentioned above \n" ); document.write( "

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