document.write( "Question 1074129: Calculate the first ten term of an arithmetic progression whose 5th term is 24 and the difference between the 7th and 10th term is 15 \n" ); document.write( "
Algebra.Com's Answer #688855 by Edwin McCravy(20060)\"\" \"About 
You can put this solution on YOUR website!
\r\n" );
document.write( "Since there are only 10 terms, it's just as easy not to\r\n" );
document.write( "use formulas, especially since we're going to have to\r\n" );
document.write( "calculate all the terms:\r\n" );
document.write( "\r\n" );
document.write( "Start with a5 = 24, subtract d each time for the \r\n" );
document.write( "terms before the 5th and add d each time for the\r\n" );
document.write( "terms after 5th:\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( " a1 = 24-4d, \r\n" );
document.write( " a2 = 24-3d, \r\n" );
document.write( " a3 = 24-2d, \r\n" );
document.write( " a4 = 24-d, \r\n" );
document.write( " a5 = 24, \r\n" );
document.write( " a6 = 24+d,\r\n" );
document.write( " a7 = 24+2d, \r\n" );
document.write( " a8 = 24+3d,\r\n" );
document.write( " a9 = 24+4d, \r\n" );
document.write( "a10 = 24+5d \r\n" );
document.write( "\r\n" );
document.write( "a7 - a10 = (24+2d) - (24+5d) = 15\r\n" );
document.write( "                 24+2d-24-5d = 15\r\n" );
document.write( "                         -3d = 15\r\n" );
document.write( "                           d = -5\r\n" );
document.write( "                          \r\n" );
document.write( "\r\n" );
document.write( " a1 = 24-4d = 24-4(-5) = 24+20 = 44 \r\n" );
document.write( " a2 = 44+(-5) = 39 \r\n" );
document.write( " a3 = 39+(-5) = 34  \r\n" );
document.write( " a4 = 34+(-5) = 29 \r\n" );
document.write( " a5 = 24           <-- given, which checks, since 24=29+(-5) \r\n" );
document.write( " a6 = 24+(-5) = 19\r\n" );
document.write( " a7 = 19+(-5) = 14 \r\n" );
document.write( " a8 = 14+(-5) = 9\r\n" );
document.write( " a9 =  9+(-5) = 4  \r\n" );
document.write( "a10 =  9+(-5) = -1\r\n" );
document.write( "\r\n" );
document.write( "Checking: a7 - a10 = 14-(-1) = 14+1 = 15\r\n" );
document.write( "\r\n" );
document.write( "Edwin
\n" ); document.write( "
\n" );