document.write( "Question 765924: 1...The sum of the two squares of two numbers is 4 and the difference of the squares of those two numbers is 1. Find the numbers\r
\n" ); document.write( "\n" ); document.write( "2...The sum of the square of the first number and the twice of the square of the second number is 6 and the twice of the first number take away the second number is 2. Find the two numbers.\r
\n" ); document.write( "\n" ); document.write( "Thanks :D
\n" ); document.write( "

Algebra.Com's Answer #466510 by MaartenRU(13)\"\" \"About 
You can put this solution on YOUR website!
1.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Let's call the two numbers x and y. Then
\n" ); document.write( "\"x%5E2%2By%5E2=4\" and
\n" ); document.write( "\"x%5E2-y%5E2=1\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Now we can see that, by subtracting the second equation from the first one, that
\n" ); document.write( "\"2y%5E2=3\"
\n" ); document.write( "So
\n" ); document.write( "\"y%5E2=3%2F2\"
\n" ); document.write( "And
\n" ); document.write( "\"y=sqrt%283%2F2%29\" or \"y=-sqrt%283%2F2%29\"\r
\n" ); document.write( "\n" ); document.write( "Substituting this into the first equation gives us
\n" ); document.write( "\"x%5E2%2B3%2F2=4\"
\n" ); document.write( "So
\n" ); document.write( "\"x%5E2=5%2F2\"
\n" ); document.write( "And therefore
\n" ); document.write( "\"x=sqrt%285%2F2%29\" or \"x=-sqrt%285%2F2%29\"\r
\n" ); document.write( "\n" ); document.write( "2.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Same idea here. We're calling the two numbers x and y. We get
\n" ); document.write( "\"x%5E2%2B2y%5E2=6\"
\n" ); document.write( "\"2x-y=2\"
\n" ); document.write( "Now the problem is a bit trickier though. We can't really find the value of either x or y immediately, so we're going to use substitution.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "According to the second equation,
\n" ); document.write( "\"2x-y=2\"
\n" ); document.write( "We can rewrite this as
\n" ); document.write( "\"y=2x-2\"
\n" ); document.write( "Now we substitute this 'implicit' value of y into our first equation:\r
\n" ); document.write( "\n" ); document.write( "\"x%5E2%2B2%282x-2%29%5E2=6\"
\n" ); document.write( "We'll make that a bit nicer:
\n" ); document.write( "\"x%5E2%2B2%282x-2%29%5E2=x%5E2%2B2%284x%5E2-8x%2B4%29=x%5E2%2B8x%5E2-16x%2B8=9x%5E2-16x%2B8=6\"
\n" ); document.write( "So,
\n" ); document.write( "\"9x%5E2-16x%2B2=0\"
\n" ); document.write( "Now, that's an equation we can solve. With the trusty old
\n" ); document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"
\n" ); document.write( "We get
\n" ); document.write( "
\n" ); document.write( "Dividing the numerator and denominator by two gives us
\n" ); document.write( "\"x=%281%2F9%29%2A%288%2B-sqrt%2846%29%29\"
\n" ); document.write( "And so
\n" ); document.write( "\"y=2x-2=2%2A%281%2F9%29%2A%288%2B-sqrt%2846%29%29-2\"
\n" ); document.write( "
\n" ); document.write( "
\n" );