document.write( "Question 30460: Solve the system:
\n" ); document.write( "x^2+y^2=63
\n" ); document.write( "x^2-3y^2=27\r
\n" ); document.write( "\n" ); document.write( "(A) (3 sqrt 6, 3) (3 sqrt 6, -3) (-3 sqrt 6, 3) (-3 sqrt6, -3)
\n" ); document.write( "(B) (-3 sqrt6, 3) ( -3 sqrt6, -3)
\n" ); document.write( "(C) 3 sqrt6, 3) (3 sqrt 6, -3)
\n" ); document.write( "(D) 1, sqrt 62) (1, -swrt 62) (-1, sqrt 62) (-1, -sqrt 62)\r
\n" ); document.write( "\n" ); document.write( "Please be specific as to which letter answer is correct.
\n" ); document.write( "Thanks \n" ); document.write( "
Algebra.Com's Answer #17100 by mukhopadhyay(490)\"\" \"About 
You can put this solution on YOUR website!
x^2+y^2=63
\n" ); document.write( "=> x^2=63-y^2\r
\n" ); document.write( "\n" ); document.write( "By substituting x^2 in the second equation:
\n" ); document.write( "x^2-3y^2=27
\n" ); document.write( "=>(63-y^2)-3y^2=27
\n" ); document.write( "=>-y^2-3y^2 = 27-63
\n" ); document.write( "=> -4y^2 = -36
\n" ); document.write( "=> y^2 = 9
\n" ); document.write( "=> y = 3 or y = -3\r
\n" ); document.write( "\n" ); document.write( "x^2 = 63-y^2
\n" ); document.write( "=>x^2 = 63-9
\n" ); document.write( "=>x^2 = 54
\n" ); document.write( "=>x = sqrt(54) or x = -sqrt(54)
\n" ); document.write( "=>x = 3sqrt(6) or x = -3sqrt(6)\r
\n" ); document.write( "\n" ); document.write( "Answer: x = 3 or -3; y = 3sqrt(6) or y = -3sqrt(6)
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