document.write( "Question 147154: solve the equation for y\r
\n" ); document.write( "\n" ); document.write( "3/4 +5y=20 \r
\n" ); document.write( "\n" ); document.write( "2/3x-1/2y=12
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Algebra.Com's Answer #107478 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "\"%283%2F4%29x%2B5y=20\" Start with the first equation.\r
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\n" ); document.write( "\n" ); document.write( "\"4%28%283%2Fcross%284%29%29x%2B5y%29=4%2820%29\" Multiply both sides by the LCD \"4\" to clear any fractions.\r
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\n" ); document.write( "\n" ); document.write( "\"3x%2B20y=80\" Distribute and multiply.\r
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\n" ); document.write( "\n" ); document.write( "\"%282%2F3%29x-%281%2F2%29y=12\" Move onto the next equation.\r
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\n" ); document.write( "\n" ); document.write( "\"6%28%282%2Fcross%283%29%29x-%281%2Fcross%282%29%29y%29=6%2812%29\" Multiply both sides by the LCD \"6\" to clear any fractions.\r
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\n" ); document.write( "\n" ); document.write( "\"4x-3y=72\" Distribute and multiply.\r
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\n" ); document.write( "\n" ); document.write( "So we have the given system of equations:\r
\n" ); document.write( "\n" ); document.write( "\"system%283x%2B20y=80%2C4x-3y=72%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"-4%283x%2B20y%29=-4%2880%29\" Multiply the both sides of the first equation by -4.\r
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\n" ); document.write( "\n" ); document.write( "\"-12x-80y=-320\" Distribute and multiply.\r
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\n" ); document.write( "\n" ); document.write( "\"3%284x-3y%29=3%2872%29\" Multiply the both sides of the second equation by 3.\r
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\n" ); document.write( "\n" ); document.write( "\"12x-9y=216\" 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%28-12x-80y=-320%2C12x-9y=216%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( "\"%28-12x-80y%29%2B%2812x-9y%29=%28-320%29%2B%28216%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"%28-12x%2B12x%29%2B%28-80y%2B-9y%29=-320%2B216\" Group like terms.\r
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\n" ); document.write( "\n" ); document.write( "\"0x%2B-89y=-104\" Combine like terms. Notice how the x terms cancel out.\r
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\n" ); document.write( "\n" ); document.write( "\"-89y=-104\" Simplify.\r
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\n" ); document.write( "\n" ); document.write( "\"y=%28-104%29%2F%28-89%29\" Divide both sides by \"-89\" to isolate \"y\".\r
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\n" ); document.write( "\n" ); document.write( "\"y=104%2F89\" Reduce.\r
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\n" ); document.write( "\n" ); document.write( "\"-12x-80y=-320\" Now go back to the first equation.\r
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\n" ); document.write( "\n" ); document.write( "\"-12x-80%28104%2F89%29=-320\" Plug in \"y=104%2F89\".\r
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\n" ); document.write( "\n" ); document.write( "\"-12x-8320%2F89=-320\" Multiply.\r
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\n" ); document.write( "\n" ); document.write( "\"89%28-12x-8320%2Fcross%2889%29%29=89%28-320%29\" Multiply both sides by the LCD \"89\" to clear any fractions.\r
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\n" ); document.write( "\n" ); document.write( "\"-1068x-8320=-28480\" Distribute and multiply.\r
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\n" ); document.write( "\n" ); document.write( "\"-1068x=-28480%2B8320\" Add \"8320\" to both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"-1068x=-20160\" Combine like terms on the right side.\r
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\n" ); document.write( "\n" ); document.write( "\"x=%28-20160%29%2F%28-1068%29\" Divide both sides by \"-1068\" to isolate \"x\".\r
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\n" ); document.write( "\n" ); document.write( "\"x=1680%2F89\" Reduce.\r
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\n" ); document.write( "\n" ); document.write( "So our answer is \"x=1680%2F89\" and \"y=104%2F89\".\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 two equations are consistent and independent.\r
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