document.write( "Question 991055: the difference in the ages of two brother is 6 years.if after two years the product of their ages will be 280 find their present age \n" ); document.write( "
Algebra.Com's Answer #610970 by ikleyn(52788)\"\" \"About 
You can put this solution on YOUR website!
.
\n" ); document.write( "Answer.  20  and  14 after  2 years; correspondingly,  18  and  12  is present age now.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The tip:  after two years the difference in their ages will be the same,  6 years.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Let  x  and  y  are their ages after  2  years.  Then you have the system\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"system%28x-y+=+6%2C%0D%0Axy=280%29\".\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Express  x  from the first equation, x = y+6, and substitute it into the second equation.  You will get\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "(y+6)*y = 280,\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y%5E2\" + \"6y\" - \"280\" = \"0\".\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The roots are  14  and  -20.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Only positive root suits the condition. \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Next,  take off  2  years.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "
\n" );