document.write( "Question 178005: x + 6y = -4
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Algebra.Com's Answer #133035 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
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\n" ); document.write( "\n" ); document.write( "Start with the given system of equations:\r
\n" ); document.write( "\n" ); document.write( "\"system%28x%2B6y=-4%2C3x-4y=10%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"-3%28x%2B6y%29=-3%28-4%29\" Multiply the both sides of the first equation by -3.\r
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\n" ); document.write( "\n" ); document.write( "\"-3x-18y=12\" Distribute and multiply.\r
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\n" ); document.write( "\n" ); document.write( "So we have the new system of equations:\r
\n" ); document.write( "\n" ); document.write( "\"system%28-3x-18y=12%2C3x-4y=10%29\"\r
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\n" ); document.write( "\n" ); document.write( "Now add the equations together. You can do this by simply adding the two left sides and the two right sides separately like this:\r
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\n" ); document.write( "\n" ); document.write( "\"%28-3x-18y%29%2B%283x-4y%29=%2812%29%2B%2810%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"%28-3x%2B3x%29%2B%28-18y%2B-4y%29=12%2B10\" Group like terms.\r
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\n" ); document.write( "\n" ); document.write( "\"0x%2B-22y=22\" Combine like terms.\r
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\n" ); document.write( "\n" ); document.write( "\"-22y=22\" Simplify.\r
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\n" ); document.write( "\n" ); document.write( "\"y=%2822%29%2F%28-22%29\" Divide both sides by \"-22\" to isolate \"y\".\r
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\n" ); document.write( "\n" ); document.write( "\"y=-1\" Reduce.\r
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\n" ); document.write( "\n" ); document.write( "\"-3x-18y=12\" Now go back to the first equation.\r
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\n" ); document.write( "\n" ); document.write( "\"-3x-18%28-1%29=12\" Plug in \"y=-1\".\r
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\n" ); document.write( "\n" ); document.write( "\"-3x%2B18=12\" Multiply.\r
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\n" ); document.write( "\n" ); document.write( "\"-3x=12-18\" Subtract \"18\" from both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"-3x=-6\" Combine like terms on the right side.\r
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\n" ); document.write( "\n" ); document.write( "\"x=%28-6%29%2F%28-3%29\" Divide both sides by \"-3\" to isolate \"x\".\r
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\n" ); document.write( "\n" ); document.write( "\"x=2\" Reduce.\r
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\n" ); document.write( "\n" ); document.write( "So our answer is \"x=2\" and \"y=-1\".\r
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\n" ); document.write( "\n" ); document.write( "Which form the ordered pair .\r
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\n" ); document.write( "\n" ); document.write( "This means that the system is consistent and independent.\r
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\n" ); document.write( "\n" ); document.write( "Notice when we graph the equations, we see that they intersect at . So this visually verifies our answer.\r
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\n" ); document.write( "\n" ); document.write( " Graph of \"x%2B6y=-4\" (red) and \"3x-4y=10\" (green)
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