document.write( "Question 254675: Three numbers form an arithmetic sequence, common difference being 11. If first number is decreased by 6, second number decreased by 1, and third number doubled, resulting numbers form a geometric sequence. determine the numbers that form the arithmetic sequence\r
\n" ); document.write( "\n" ); document.write( "Answer is -26, -15, -4, 14, 25, 36
\n" ); document.write( "

Algebra.Com's Answer #187022 by drk(1908)\"\" \"About 
You can put this solution on YOUR website!
Let the first term be A
\n" ); document.write( "Let the second term be A + 11
\n" ); document.write( "Let the third term be A + 22
\n" ); document.write( "we know that common difference, d, is 11.
\n" ); document.write( "--
\n" ); document.write( "A - 6, A + 10, 2(A+22)
\n" ); document.write( "is now a geometric sequence. They have common ratios which can be expressed as
\n" ); document.write( "(A+10)/(A-6) = (2A+44)/(A+10)
\n" ); document.write( "Cross multiplying, we get
\n" ); document.write( "(A+10)^2 = (2A+44)(A-6)
\n" ); document.write( "A^2 + 20A + 100 = 2A^2 + 32A -264
\n" ); document.write( "set = 0 as
\n" ); document.write( "A^2 + 12A -364 = 0
\n" ); document.write( "(A - 14)(a + 26) = 0
\n" ); document.write( "A = 14 or A = -26
\n" ); document.write( "--
\n" ); document.write( "If A = 14, then the arithmetic sequence is
\n" ); document.write( "14, 25, 36
\n" ); document.write( "and the geometric sequence is
\n" ); document.write( "8, 24, 72
\n" ); document.write( "--
\n" ); document.write( "If A = -26, then the arithmetic sequence is
\n" ); document.write( "-26, -15, -4
\n" ); document.write( "and the geometric sequence is
\n" ); document.write( "-32, -16, -8
\n" ); document.write( "
\n" );