document.write( "Question 236583: solve the system by the elimination method: x+9y=66 and -x+9y=60 \n" ); document.write( "
Algebra.Com's Answer #174115 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%2B9y=66%2C-x%2B9y=60%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( "\"%28x%2B9y%29%2B%28-1x%2B9y%29=%2866%29%2B%2860%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"%281x%2B-1x%29%2B%289y%2B9y%29=66%2B60\" Group like terms.\r
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\n" ); document.write( "\n" ); document.write( "\"0x%2B18y=126\" Combine like terms.\r
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\n" ); document.write( "\n" ); document.write( "\"18y=126\" Simplify.\r
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\n" ); document.write( "\n" ); document.write( "\"y=%28126%29%2F%2818%29\" Divide both sides by \"18\" to isolate \"y\".\r
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\n" ); document.write( "\n" ); document.write( "\"y=7\" Reduce.\r
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\n" ); document.write( "\n" ); document.write( "\"x%2B9y=66\" Now go back to the first equation.\r
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\n" ); document.write( "\n" ); document.write( "\"x%2B9%287%29=66\" Plug in \"y=7\".\r
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\n" ); document.write( "\n" ); document.write( "\"x%2B63=66\" Multiply.\r
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\n" ); document.write( "\n" ); document.write( "\"x=66-63\" Subtract \"63\" from both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"x=3\" Combine like terms on the right side.\r
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\n" ); document.write( "\n" ); document.write( "So the solutions are \"x=3\" and \"y=7\".\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%2B9y=66\" (red) and \"-x%2B9y=60\" (green)
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