document.write( "Question 830902: The 11th term of an arithmetic sequence is 57 and the sum of the first and the fourth terms is 29.Determine the first 3 terms of the sequence. . .please help me step by step \n" ); document.write( "
Algebra.Com's Answer #501008 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11\r\n" );
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document.write( "You need this formula for the nth term:\r\n" );
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document.write( "an = a1 + (n-1)d\r\n" );
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document.write( "[Some books and teachers use \"t\" for \"term\" instead of \"a\".\r\n" );
document.write( "I'll use \"a\".]\r\n" );
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\n" ); document.write( "The 11th term of an arithmetic sequence is 57
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document.write( "a11 = a1 + (11-1)d\r\n" );
document.write( "57 = a1 + 10d\r\n" );
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\n" ); document.write( "and the sum of the first and the fourth terms is 29.
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document.write( "a1 + a4 = 29\r\n" );
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document.write( "Substitute n=4 in the formula also\r\n" );
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document.write( "a4 = a1 + (4-1)d\r\n" );
document.write( "a4 = a1 + 3d\r\n" );
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document.write( "Now substitute for a4 in \r\n" );
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document.write( "a1 + a4 = 29\r\n" );
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document.write( "a1 + (a1 + 3d) = 29 \r\n" );
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document.write( "a1 + a1 + 3d = 29\r\n" );
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document.write( "2a1 + 3d = 29\r\n" );
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document.write( "So you have this system of equations:\r\n" );
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document.write( "57 = a1 + 10d\r\n" );
document.write( "2a1 + 3d = 29\r\n" );
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document.write( "Solve the first for a1\r\n" );
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document.write( "57-10d = a1\r\n" );
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document.write( "Substitute in \r\n" );
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document.write( "2a1 + 3d = 29\r\n" );
document.write( "2(57-10d) + 3d = 29\r\n" );
document.write( "114 - 20d + 3d = 29\r\n" );
document.write( "     114 - 17d = 29\r\n" );
document.write( "          -17d = -85\r\n" );
document.write( "             d = \"%28-85%29%2F%28-17%29\"\r\n" );
document.write( "             d = 5\r\n" );
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document.write( "Substitute d=5 in \r\n" );
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document.write( "57-10d = a1\r\n" );
document.write( "57-10(5) = a1\r\n" );
document.write( "57-50 = a1\r\n" );
document.write( "7 = a1\r\n" );
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document.write( "So the sequence starts with a1=7 and adds d=5 each time.\r\n" );
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document.write( "To check, let's write them all out and see if the llth terms comes out\r\n" );
document.write( "to be 57. \r\n" );
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document.write( "7, 12, 17, 22, 27, 32, 37, 42, 47, 52, 57\r\n" );
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document.write( "The last one came out 57.  Count them.  There are 11.  So it's correct. \r\n" );
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\n" ); document.write( "Determine the first 3 terms of the sequence.
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document.write( "7, 12, 17\r\n" );
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document.write( "Edwin
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