document.write( "Question 1203795: the second term of an arithmetic is 12 and the 6th term is 40. What is the common difference? \n" ); document.write( "
Algebra.Com's Answer #839648 by math_tutor2020(3817)\"\" \"About 
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\n" ); document.write( "a1 = first term, a2 = second term, etc
\n" ); document.write( "d = common difference = the gap from term to term\r
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\n" ); document.write( "\n" ); document.write( "a2 = 12
\n" ); document.write( "a3 = a2 + d = 12 + d
\n" ); document.write( "a4 = a3 + d = (12+d) + d = 12+2d
\n" ); document.write( "a5 = a4 + d = (12+2d) + d = 12+3d
\n" ); document.write( "a6 = a5 + d = (12+3d) + d = 12+4d\r
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\n" ); document.write( "\n" ); document.write( "a6 = 40
\n" ); document.write( "12+4d = 40
\n" ); document.write( "4d = 40-12
\n" ); document.write( "4d = 28
\n" ); document.write( "d = 28/4
\n" ); document.write( "d = 7 is the common difference\r
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\n" ); document.write( "\n" ); document.write( "Verification
\n" ); document.write( "a2 = 12
\n" ); document.write( "a3 = a2 + d = 12+7 = 19
\n" ); document.write( "a4 = a3 + d = 19+7 = 26
\n" ); document.write( "a5 = a4 + d = 26+7 = 33
\n" ); document.write( "a6 = a5 + d = 33+7 = 40
\n" ); document.write( "We arrive at a6 = 40 to confirm the answer is correct.\r
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\n" ); document.write( "\n" ); document.write( "The sequence is 5,12,19,26,33,40,... that starts at 5 and increments by 7 each time we need a new term.
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