document.write( "Question 978265: Under root x+y=7
\n" ); document.write( "X+under rooty=11,find the value of x and y \n" ); document.write( "

Algebra.Com's Answer #599736 by rothauserc(4718) $\"\"$ $\"About$

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square root(x+y) = 7
\n" ); document.write( "x + square root(y) = 11
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\n" ); document.write( "square both sides of = in first equation
\n" ); document.write( "x+y = 49
\n" ); document.write( "y = 49 - x
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\n" ); document.write( "second equation subtract x from both sides of =
\n" ); document.write( "square root(y) = 11 - x
\n" ); document.write( "square both sides of =
\n" ); document.write( "y = 121 - 22x + x^2
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\n" ); document.write( "we have two equations in two unknowns
\n" ); document.write( "y = 49 -x
\n" ); document.write( "y = 121 - 22x + x^2
\n" ); document.write( "substitute for y in second equation
\n" ); document.write( "49 - x = 121 - 22x + x^2
\n" ); document.write( "x^2 - 21x + 72 = 0
\n" ); document.write( "use quadratic formula to solve for x
\n" ); document.write( "x = (21 + 12.369316877) / 2 = 16.684658439
\n" ); document.write( "x = (21 - 12.369316877) / 2 = 4.315341562
\n" ); document.write( "our solution is
\n" ); document.write( "x = 16.684658439 or x = 4.315341562 \n" ); document.write( "

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