document.write( "Question 125686: Solve the system by substitution
\n" ); document.write( "2x+2y=0
\n" ); document.write( " y=4x+0
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Algebra.Com's Answer #92050 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "Start with the given system\r
\n" ); document.write( "\n" ); document.write( "\"2x%2B2y=0\"
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\n" ); document.write( "\n" ); document.write( "\"2x%2B2%282x%29=0\" Plug in \"y=2x\" into the first equation. In other words, replace each \"y\" with \"2x\". Notice we've eliminated the \"y\" variables. So we now have a simple equation with one unknown.\r
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\n" ); document.write( "\n" ); document.write( "\"2x%2B4x=0\" Multiply\r
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\n" ); document.write( "\n" ); document.write( "\"6x=0\" Combine like terms on the left side\r
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\n" ); document.write( "\n" ); document.write( "\"x=%280%29%2F%286%29\" Divide both sides by 6 to isolate x\r
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\n" ); document.write( "\n" ); document.write( "\"x=0\" Divide\r
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\n" ); document.write( "\n" ); document.write( "Now that we know that \"x=0\", we can plug this into \"y=2x\" to find \"y\"\r
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\n" ); document.write( "\n" ); document.write( "\"y=2%280%29\" Substitute \"0\" for each \"x\"\r
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\n" ); document.write( "\n" ); document.write( "\"y=0\" Simplify\r
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\n" ); document.write( "\n" ); document.write( "So our answer is \"x=0\" and \"y=0\" which also looks like \r
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\n" ); document.write( "\n" ); document.write( "Notice if we graph the two equations, we can see that their intersection is at . So this verifies our answer.\r
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\n" ); document.write( "\n" ); document.write( "\"+graph%28+500%2C+500%2C+-5%2C+5%2C+-5%2C+5%2C+-x%2C+2x%29+\" Graph of \"2x%2B2y=0\" (red) and \"y=2x\" (green)\r
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