document.write( "Question 195945: Find all the solutions of the following systems of equations if possible. If a system has no solution, explain why it does not.\r
\n" ); document.write( "\n" ); document.write( "(a) 3X – Y = 3 (b) 2X – Y = 1 (c) 2X – Y = 1
\n" ); document.write( " 3X +Y = 15 2Y – 4X = 3 2Y – 4X = (-2)
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Algebra.Com's Answer #146914 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
I'll do the two problems to get you started\r
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\n" ); document.write( "\n" ); document.write( "A)\r
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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%283x-y=3%2C3x%2By=15%29\"\r
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\n" ); document.write( "\n" ); document.write( "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( "\"%283x-y%29%2B%283x%2By%29=%283%29%2B%2815%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"%283x%2B3x%29%2B%28-y%2By%29=3%2B15\" Group like terms.\r
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\n" ); document.write( "\n" ); document.write( "\"6x%2B0y=18\" Combine like terms.\r
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\n" ); document.write( "\n" ); document.write( "\"6x=18\" Simplify.\r
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\n" ); document.write( "\n" ); document.write( "\"x=%2818%29%2F%286%29\" Divide both sides by \"6\" 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( "\"3x-y=3\" Now go back to the first equation.\r
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\n" ); document.write( "\n" ); document.write( "\"3%283%29-y=3\" Plug in \"x=3\".\r
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\n" ); document.write( "\n" ); document.write( "\"9-y=3\" Multiply.\r
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\n" ); document.write( "\n" ); document.write( "\"-y=3-9\" Subtract \"9\" from both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"-y=-6\" Combine like terms on the right side.\r
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\n" ); document.write( "\n" ); document.write( "\"y=%28-6%29%2F%28-1%29\" Divide both sides by \"-1\" to isolate \"y\".\r
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\n" ); document.write( "\n" ); document.write( "\"y=6\" Reduce.\r
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\n" ); document.write( "\n" ); document.write( "So the solutions are \"x=3\" and \"y=6\".\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 \"3x-y=3\" (red) and \"3x%2By=15\" (green) \r
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\n" ); document.write( "\n" ); document.write( "\"2y-4x=3\" Start with the second equation.\r
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\n" ); document.write( "\n" ); document.write( "\"-4x%2B2y=3\" Rearrange the terms.\r
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\n" ); document.write( "\n" ); document.write( "So we have the system of equations:\r
\n" ); document.write( "\n" ); document.write( "\"system%282x-y=1%2C-4x%2B2y=3%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"2%282x-y%29=2%281%29\" Multiply the both sides of the first equation by 2.\r
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\n" ); document.write( "\n" ); document.write( "\"4x-2y=2\" 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%284x-2y=2%2C-4x%2B2y=3%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( "\"%284x-2y%29%2B%28-4x%2B2y%29=%282%29%2B%283%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"%284x%2B-4x%29%2B%28-2y%2B2y%29=2%2B3\" Group like terms.\r
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\n" ); document.write( "\n" ); document.write( "\"0x%2B0y=5\" Combine like terms.\r
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\n" ); document.write( "\n" ); document.write( "\"0=5\"Simplify.\r
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\n" ); document.write( "\n" ); document.write( "Since \"0=5\" is never true, this means that there are no solutions. \r
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\n" ); document.write( "\n" ); document.write( "So the system is inconsistent.
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