document.write( "Question 199100: Solve algebraically and check:
\n" ); document.write( " 2x+4y=2
\n" ); document.write( " 3x-6y=15
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Algebra.Com's Answer #149562 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "Start with the given system of equations:\r
\n" ); document.write( "\n" ); document.write( "\"system%282x%2B4y=2%2C3x-6y=15%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"3%282x%2B4y%29=3%282%29\" Multiply the both sides of the first equation by 3.\r
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\n" ); document.write( "\n" ); document.write( "\"6x%2B12y=6\" Distribute and multiply.\r
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\n" ); document.write( "\n" ); document.write( "\"2%283x-6y%29=2%2815%29\" Multiply the both sides of the second equation by 2.\r
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\n" ); document.write( "\n" ); document.write( "\"6x-12y=30\" 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%286x%2B12y=6%2C6x-12y=30%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( "\"%286x%2B12y%29%2B%286x-12y%29=%286%29%2B%2830%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"%286x%2B6x%29%2B%2812y%2B-12y%29=6%2B30\" Group like terms.\r
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\n" ); document.write( "\n" ); document.write( "\"12x%2B0y=36\" Combine like terms.\r
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\n" ); document.write( "\n" ); document.write( "\"12x=36\" Simplify.\r
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\n" ); document.write( "\n" ); document.write( "\"x=%2836%29%2F%2812%29\" Divide both sides by \"12\" to isolate \"x\".\r
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\n" ); document.write( "\n" ); document.write( "\"x=3\" Reduce.\r
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\n" ); document.write( "\n" ); document.write( "\"6x%2B12y=6\" Now go back to the first equation.\r
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\n" ); document.write( "\n" ); document.write( "\"6%283%29%2B12y=6\" Plug in \"x=3\".\r
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\n" ); document.write( "\n" ); document.write( "\"18%2B12y=6\" Multiply.\r
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\n" ); document.write( "\n" ); document.write( "\"12y=6-18\" Subtract \"18\" from both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"12y=-12\" Combine like terms on the right side.\r
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\n" ); document.write( "\n" ); document.write( "\"y=%28-12%29%2F%2812%29\" Divide both sides by \"12\" 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( "So the solutions are \"x=3\" 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 \"2x%2B4y=2\" (red) and \"3x-6y=15\" (green) \r
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\n" ); document.write( "\n" ); document.write( "I'll let you do the check.
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