document.write( "Question 120664: solve each systems of equations algebraically\r
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\n" ); document.write( "38. -3x+12y=6
\n" ); document.write( " 2x-8y=6
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Algebra.Com's Answer #88447 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
#38\r
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Solved by pluggable solver: Solving a linear system of equations by subsitution

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\n" ); document.write( " Lets start with the given system of linear equations
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\n" ); document.write( " \"-3%2Ax%2B12%2Ay=6\"
\n" ); document.write( " \"2%2Ax-8%2Ay=6\"
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\n" ); document.write( " Now in order to solve this system by using substitution, we need to solve (or isolate) one variable. I'm going to choose y.
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\n" ); document.write( " Solve for y for the first equation
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\n" ); document.write( " \"12%2Ay=6%2B3%2Ax\"Add \"3%2Ax\" to both sides
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\n" ); document.write( " \"y=%286%2B3%2Ax%29%2F12\" Divide both sides by 12.
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\n" ); document.write( " Which breaks down and reduces to
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\n" ); document.write( " \"y=1%2F2%2B%281%2F4%29%2Ax\" Now we've fully isolated y
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\n" ); document.write( " Since y equals \"1%2F2%2B%281%2F4%29%2Ax\" we can substitute the expression \"1%2F2%2B%281%2F4%29%2Ax\" into y of the 2nd equation. This will eliminate y so we can solve for x.
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\n" ); document.write( " \"2%2Ax%2B-8%2Ahighlight%28%281%2F2%2B%281%2F4%29%2Ax%29%29=6\" Replace y with \"1%2F2%2B%281%2F4%29%2Ax\". Since this eliminates y, we can now solve for x.
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\n" ); document.write( " \"2%2Ax-8%2A%281%2F2%29-8%281%2F4%29x=6\" Distribute -8 to \"1%2F2%2B%281%2F4%29%2Ax\"
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\n" ); document.write( " \"2%2Ax-8%2F2-%288%2F4%29%2Ax=6\" Multiply
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\n" ); document.write( " \"2%2Ax-4-2%2Ax=6\" Reduce any fractions
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\n" ); document.write( " \"2%2Ax-2%2Ax=6%2B4\"Add \"4\" to both sides
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\n" ); document.write( " \"2%2Ax-2%2Ax=10\" Combine the terms on the right side
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\n" ); document.write( " \"0%2Ax=10\" Now combine the terms on the left side.
\n" ); document.write( " \"0%2F1=10%2F1\" Since this expression is not true, we have an inconsistency.
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\n" ); document.write( " So there are no solutions. The simple reason is the 2 equations represent 2 parallel lines that will never intersect. Since no intersections occur, no solutions exist.
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\n" ); document.write( " graph of \"-3%2Ax%2B12%2Ay=6\" (red) and \"2%2Ax-8%2Ay=6\" (green) (hint: you may have to solve for y to graph these)
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\n" ); document.write( " and we can see that the two equations are parallel and will never intersect. So this system is inconsistent

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