document.write( "Question 995318: Solve the system x+y=9 and 4x+y=9 \n" ); document.write( "

Algebra.Com's Answer #614081 by MathLover1(20850) $\"\"$ $\"About$

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\n" ); document.write( " $\"x%2By=9\"$ ...eq.1
\n" ); document.write( " $\"4x%2By=9\"$ ...eq.2
\n" ); document.write( "----------------------subtract eq.1 from eq.2\r
\n" ); document.write( "\n" ); document.write( " $\"4x%2By-%28x%2By%29=9-9\"$
\n" ); document.write( " $\"4x%2Bcross%28y%29-x-cross%28y%29=0\"$
\n" ); document.write( " $\"3x=0\"$
\n" ); document.write( " $\"highlight%28x=0%29\"$ \r
\n" ); document.write( "\n" ); document.write( "go to eq.1, plug in $\"0\"$ for $\"x\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"x%2By=9\"$ ...eq.1
\n" ); document.write( " $\"0%2By=9\"$
\n" ); document.write( " $\"highlight%28y=9%29\"$ \r
\n" ); document.write( "\n" ); document.write( "so, these two lines intersecting each other in one point, ( $\"0\"$ , $\"9\"$ )\r
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\n" ); document.write( "\n" ); document.write( " $\"+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+-x%2B9%2C-4x%2B9%29+\"$ \r
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