document.write( "Question 1119562: Hi, could you help me with this question here please?\r
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document.write( "\"Write the explicit rule for this arithmetic sequence. The 4th term = 5, and the 10th term = 23\"\r
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document.write( "Thank you! \n" );
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Algebra.Com's Answer #735120 by Theo(13342)![]() ![]() You can put this solution on YOUR website! the formula for an arithmetic sequence is:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "An = A1 + (n-1) * d\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "your 4th term is equal to 5 and your 10th term is equal to 23.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "using the formula, you get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "A4 = A1 + (4-1) * d\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "A10 = A1 + (9-1) * d\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "these simplify to:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "A4 = A1 + 3d \n" ); document.write( "A10 = A1 + 9d\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you are given that A4 = 5 and A10 = 23.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the formulas become:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "5 = A1 + 3d \n" ); document.write( "23 = A1 + 9d\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "subtract the first formula from the second to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "18 = 6d\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "solve for d to get d = 3.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "in both equations, replace d with 3 to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "5 = A1 + 3 * 3 \n" ); document.write( "23 = A1 + 9 * 3\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "these simplify to:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "5 = A1 + 9 \n" ); document.write( "23 = A1 + 27\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "solve for A1 in both equations to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "A1 = -4 in the first equation. \n" ); document.write( "A1 = -4 in the second equation.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "that's good, since A1 needed to be the same in both equations.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "since A1 = -4 and d = 3, your sequence is as follows:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \r\n" ); document.write( "\r\n" ); document.write( "term number term value\r\n" ); document.write( "1 -4\r\n" ); document.write( "2 -1\r\n" ); document.write( "3 2\r\n" ); document.write( "4 5 ***** 4th term in sequence.\r\n" ); document.write( "5 8\r\n" ); document.write( "6 11\r\n" ); document.write( "7 14\r\n" ); document.write( "8 17 \r\n" ); document.write( "9 20\r\n" ); document.write( "10 23 ***** 10th term in sequence.\r\n" ); document.write( "\r\n" ); document.write( "\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "here's a reference on arithmetic sequences.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "https://www.mathsisfun.com/algebra/sequences-sums-arithmetic.html\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |