document.write( "Question 710243: If the line passing through the points
\n" ); document.write( "(a, 1) and (15, 6)
\n" ); document.write( " is parallel to the line passing through the points
\n" ); document.write( "(14, 7) and (a + 2, 1),
\n" ); document.write( " what is the value of a? \n" ); document.write( "
Algebra.Com's Answer #436928 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
\r\n" );
document.write( "Find the slope of the first line using the slope formula:\r\n" );
document.write( "\r\n" );
document.write( "m = \"%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29\"\r\n" );
document.write( "\r\n" );
document.write( "where (x1,y1) = (a,1)\r\n" );
document.write( "\r\n" );
document.write( "and where (x2,y2) = (15,6)\r\n" );
document.write( "\r\n" );
document.write( "m = \"%286-1%29%2F%2815-a%29\"\r\n" );
document.write( "\r\n" );
document.write( "m = \"5%2F%2815-a%29\"\r\n" );
document.write( "\r\n" );
document.write( "Find the slope of the second line using the slope formula:\r\n" );
document.write( "\r\n" );
document.write( "m = \"%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29\"\r\n" );
document.write( "\r\n" );
document.write( "where (x1,y1) = (14,7)\r\n" );
document.write( "\r\n" );
document.write( "and where (x2,y2) = (a+2,1)\r\n" );
document.write( "\r\n" );
document.write( "m = \"%281-7%29%2F%28%28a%2B2%29-14%29\"\r\n" );
document.write( "\r\n" );
document.write( "m = \"-6%2F%28a%2B2-14%29\"\r\n" );
document.write( "\r\n" );
document.write( "m = \"-6%2F%28a-12%29\"\r\n" );
document.write( "\r\n" );
document.write( "Since they are parallel their slopes are equal, so we \r\n" );
document.write( "set the two slopes equal:\r\n" );
document.write( "\r\n" );
document.write( "\"5%2F%2815-a%29\" = \"-6%2F%28a-12%29\"\r\n" );
document.write( "\r\n" );
document.write( "Cross multiply and solve and get a=30\r\n" );
document.write( "\r\n" );
document.write( "Edwin
\n" ); document.write( "
\n" );