document.write( "Question 103695: 2x - y = 4
\n" ); document.write( "2x - y = 6\r
\n" ); document.write( "\n" ); document.write( "there is also a graph with this. help
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Algebra.Com's Answer #75381 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
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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( " \"2%2Ax-1%2Ay=4\"
\n" ); document.write( " \"2%2Ax-1%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( " \"-1%2Ay=4-2%2Ax\"Subtract \"2%2Ax\" from both sides
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\n" ); document.write( " \"y=%284-2%2Ax%29%2F-1\" Divide both sides by -1.
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\n" ); document.write( " Which breaks down and reduces to
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\n" ); document.write( " \"y=-4%2B2%2Ax\" Now we've fully isolated y
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\n" ); document.write( " Since y equals \"-4%2B2%2Ax\" we can substitute the expression \"-4%2B2%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-1%2Ahighlight%28%28-4%2B2%2Ax%29%29=6\" Replace y with \"-4%2B2%2Ax\". Since this eliminates y, we can now solve for x.
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\n" ); document.write( " \"2%2Ax-1%2A%28-4%29-1%282%29x=6\" Distribute -1 to \"-4%2B2%2Ax\"
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\n" ); document.write( " \"2%2Ax%2B4-2%2Ax=6\" Multiply
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\n" ); document.write( " \"2%2Ax%2B4-2%2Ax=6\" Reduce any fractions
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\n" ); document.write( " \"2%2Ax-2%2Ax=6-4\" Subtract \"4\" from both sides
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\n" ); document.write( " \"2%2Ax-2%2Ax=2\" Combine the terms on the right side
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\n" ); document.write( " \"0%2Ax=2\" Now combine the terms on the left side.
\n" ); document.write( " \"0%2F1=2%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 \"2%2Ax-1%2Ay=4\" (red) and \"2%2Ax-1%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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