document.write( "Question 244750: 3x-5y=-3,-9x-15y=9 how do you solve using the elimination method? \n" ); document.write( "
Algebra.Com's Answer #178990 by jim_thompson5910(35256)\"\" \"About 
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\n" ); document.write( "Start with the given system of equations:\r
\n" ); document.write( "\n" ); document.write( "\"system%283x-5y=-3%2C-9x-15y=9%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"3%283x-5y%29=3%28-3%29\" Multiply the both sides of the first equation by 3.\r
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\n" ); document.write( "\n" ); document.write( "\"9x-15y=-9\" 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%289x-15y=-9%2C-9x-15y=9%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( "\"%289x-15y%29%2B%28-9x-15y%29=%28-9%29%2B%289%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"%289x%2B-9x%29%2B%28-15y%2B-15y%29=-9%2B9\" Group like terms.\r
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\n" ); document.write( "\n" ); document.write( "\"0x%2B-30y=0\" Combine like terms.\r
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\n" ); document.write( "\n" ); document.write( "\"-30y=0\" Simplify.\r
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\n" ); document.write( "\n" ); document.write( "\"y=%280%29%2F%28-30%29\" Divide both sides by \"-30\" to isolate \"y\".\r
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\n" ); document.write( "\n" ); document.write( "\"y=0\" Reduce.\r
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\n" ); document.write( "\n" ); document.write( "\"9x-15y=-9\" Now go back to the first equation.\r
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\n" ); document.write( "\n" ); document.write( "\"9x-15%280%29=-9\" Plug in \"y=0\".\r
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\n" ); document.write( "\n" ); document.write( "\"9x=-9\" Multiply.\r
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\n" ); document.write( "\n" ); document.write( "\"x=%28-9%29%2F%289%29\" Divide both sides by \"9\" to isolate \"x\".\r
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\n" ); document.write( "\n" ); document.write( "\"x=-1\" Reduce.\r
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\n" ); document.write( "\n" ); document.write( "So the solutions are \"x=-1\" and \"y=0\".\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-5y=-3\" (red) and \"-9x-15y=9\" (green)
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