document.write( "Question 175696: If one number is equal to two times a second number. Two times the first number plus two times the second number is 24. If you let x stand for the first number and y for the second, what are the two numbers? \n" ); document.write( "
Algebra.Com's Answer #130799 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
\"one number is equal to two times a second number\" translates to \"x=2y\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"Two times the first number plus two times the second number is 24\" means that \"2x%2B2y=24\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So we have the system:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x=2y\"
\n" ); document.write( "\"2x%2B2y=24\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"2%282y%29%2B2y=24\" Plug in \"x=2y\" into the second equation. In other words, replace each \"x\" with \"2y\". Notice we've eliminated the \"x\" variables. So we now have a simple equation with one unknown.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"4y%2B2y=24\" Distribute\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"6y=24\" Combine like terms on the left side\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y=%2824%29%2F%286%29\" Divide both sides by 6 to isolate y\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y=4\" Divide\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Now that we know that \"y=4\", we can plug this into \"x=2y\" to find \"x\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x=2%284%29\" Substitute \"4\" for each \"y\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x=8\" Multiply\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So our answer is \"x=8\" and \"y=4\" which means that the first number is 8 and the second number is 4.\r
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );