document.write( "Question 1084377: What is the sum of the first 50 terms of the arithmetic sequence in which the 3rd term is 10 and the 15th term is 22? \n" ); document.write( "

Algebra.Com's Answer #698489 by ikleyn(52781) $\"\"$ $\"About$

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document.write( "  =   = 10     (1)\r\n" );
document.write( " =  = 22     (2)\r\n" );
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document.write( "Subtract equation (1) from equation (2) (both sides). You will get\r\n" );
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document.write( "12d = 22 - 10 = 12.   Hence, d = 1.\r\n" );
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document.write( "Thus you found the common difference.  It is 1.\r\n" );
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document.write( "Then the first term of the AP is   =  = 10 - 2*1 = 8.\r\n" );
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document.write( "The last term of the AP is  =  = 8 + 49*1 = 57.\r\n" );
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document.write( "Now you can find the sum of the first 50 terms of the AP as\r\n" );
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document.write( " =  =  = calculate.\r\n" );
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\n" ); document.write( "\n" ); document.write( "On arithmetic progressions, see the lessons in this site:\r
\n" ); document.write( "\n" ); document.write( "    - Arithmetic progressions\r
\n" ); document.write( "\n" ); document.write( "    - The proofs of the formulas for arithmetic progressions \r
\n" ); document.write( "\n" ); document.write( "    - Problems on arithmetic progressions \r
\n" ); document.write( "\n" ); document.write( "    - Word problems on arithmetic progressions\r
\n" ); document.write( "\n" ); document.write( "    - Mathematical induction and arithmetic progressions\r
\n" ); document.write( "\n" ); document.write( "    - One characteristic property of arithmetic progressions\r
\n" ); document.write( "\n" ); document.write( "    - Solved problems on arithmetic progressions \r
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\n" ); document.write( "\n" ); document.write( "Also, you have this free of charge online textbook in ALGEBRA-II in this site\r
\n" ); document.write( "\n" ); document.write( "    - ALGEBRA-II - YOUR ONLINE TEXTBOOK.\r
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\n" ); document.write( "\n" ); document.write( "The referred lessons are the part of this online textbook under the topic \"Arithmetic progressions\".\r
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