document.write( "Question 27708: what the solution for the equations x^2-y^2=9
\n" ); document.write( " x^2+9y2=169
\n" ); document.write( " thank you \n" ); document.write( "

Algebra.Com's Answer #15088 by wuwei96815(245) $\"\"$ $\"About$

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x^2-y^2=9
\n" ); document.write( "x^2+9y^2=169\r
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\n" ); document.write( "\n" ); document.write( "This set of equations can be solved by elimination and sustitution. First, multiply the first equation by -1, and then add the two equations together. This will eliminate x and allow us to solve for y.\r
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\n" ); document.write( "\n" ); document.write( "-x^2+y^2=-9
\n" ); document.write( "x^2+9y^2=169
\n" ); document.write( "____________
\n" ); document.write( "10y^2=160
\n" ); document.write( "y^2=16
\n" ); document.write( "y=4\r
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\n" ); document.write( "\n" ); document.write( "Now that you have the value of y you can substitute it in any one of the two equations and solve for x.
\n" ); document.write( "Let's use the first equation.\r
\n" ); document.write( "\n" ); document.write( "x^2-y^2=9
\n" ); document.write( "x^2-(4)^2=9
\n" ); document.write( "x^2-16=9
\n" ); document.write( "x^2=25
\n" ); document.write( "x=5\r
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\n" ); document.write( "\n" ); document.write( "I hope that you were able to follow the solution. To check our answer substitute x=5 and y=4 in the equations. \n" ); document.write( "

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