document.write( "Question 1014351: Thr 20th term of an arithmetic progression is 10 and the 50th term is 70, find the first term and the common difference
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Algebra.Com's Answer #630648 by ikleyn(52790) $\"\"$ $\"About$

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\n" ); document.write( "Thr 20th term of an arithmetic progression is 10 and the 50th term is 70, find the first term and the common difference
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document.write( "The formula for the n-th term of an Arithmetic progression is \r\n" );
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document.write( " =  + (n-1)*d.\r\n" );
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document.write( "So, \r\n" );
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document.write( " =  + 19*d,   (1)\r\n" );
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document.write( " =  + 49*d.   (2)\r\n" );
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document.write( "Now, distract (1) from (2). You will get\r\n" );
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document.write( "70 - 10 = 30*d.\r\n" );
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document.write( "Find d from there.\r\n" );
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document.write( "Then think what to do next.\r\n" );
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