document.write( "Question 758206: Xsq + Ysq = 9. X + Y = 2. Give two answers for X & Y \n" ); document.write( "

Algebra.Com's Answer #461333 by kmadison(20) $\"\"$ $\"About$

You can put this solution on YOUR website!
2 equations, 2 unknowns:\r
\n" ); document.write( "\n" ); document.write( " $\"Y+=+X+-+2\"$ \r
\n" ); document.write( "\n" ); document.write( "Now plug into the other equation:\r
\n" ); document.write( "\n" ); document.write( " $\"X%5E2+%2B+Y%5E2+=+9\"$ --> $\"X%5E2+%2B+%28X-2%29%5E2+=+9\"$ \r
\n" ); document.write( "\n" ); document.write( "Expanding the 2nd portion:
\n" ); document.write( " $\"X%5E2+%2B+%28X%5E2+-+4X+%2B+4%29+=+9\"$ \r
\n" ); document.write( "\n" ); document.write( "Now combine like terms and subtract 9 from both sides:
\n" ); document.write( " $\"2X%5E2+-+4X+-+5+=+0\"$ \r
\n" ); document.write( "\n" ); document.write( "From here we use the quadratic formula to determine the 2 solutions for X:
\n" ); document.write( " $\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"$ \r
\n" ); document.write( "\n" ); document.write( "From the formula we get 2 solutions for X: $\"X+=+1-sqrt%287%2F2%29\"$ and $\"X+=+1+%2B+sqrt%287%2F2%29\"$ \r
\n" ); document.write( "\n" ); document.write( "Plug these into $\"Y+=+X+-+2\"$ and you will get your solutions for Y. \n" ); document.write( "

\n" );