document.write( "Question 1130673: Use substitution to solve the system. (Simplify your answer completely. If there is no solution, enter NO SOLUTION.)\r
\n" ); document.write( "\n" ); document.write( "3y = −12x + 8
\n" ); document.write( "4x + y = 3
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Algebra.Com's Answer #747275 by MathLover1(20850)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "\"3y+=+-12x+%2B+8\"
\n" ); document.write( "\"4x+%2B+y+=+3\"\r
\n" ); document.write( "\n" ); document.write( "in standard form:\r
\n" ); document.write( "\n" ); document.write( "\"12x%2B3y+=+8\"
\n" ); document.write( "\"4x+%2B+y+=+3\"\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( " \"12%2Ax%2B3%2Ay=8\"
\n" ); document.write( " \"4%2Ax%2B1%2Ay=3\"
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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( " \"3%2Ay=8-12%2Ax\"Subtract \"12%2Ax\" from both sides
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\n" ); document.write( " \"y=%288-12%2Ax%29%2F3\" Divide both sides by 3.
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\n" ); document.write( " Which breaks down and reduces to
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\n" ); document.write( " \"y=8%2F3-4%2Ax\" Now we've fully isolated y
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\n" ); document.write( " Since y equals \"8%2F3-4%2Ax\" we can substitute the expression \"8%2F3-4%2Ax\" into y of the 2nd equation. This will eliminate y so we can solve for x.
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\n" ); document.write( " \"4%2Ax%2B1%2Ahighlight%28%288%2F3-4%2Ax%29%29=3\" Replace y with \"8%2F3-4%2Ax\". Since this eliminates y, we can now solve for x.
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\n" ); document.write( " \"4%2Ax%2B1%2A%288%2F3%29%2B1%28-4%29x=3\" Distribute 1 to \"8%2F3-4%2Ax\"
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\n" ); document.write( " \"4%2Ax%2B8%2F3-4%2Ax=3\" Multiply
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\n" ); document.write( " \"4%2Ax%2B8%2F3-4%2Ax=3\" Reduce any fractions
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\n" ); document.write( " \"4%2Ax-4%2Ax=3-8%2F3\" Subtract \"8%2F3\" from both sides
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\n" ); document.write( " \"4%2Ax-4%2Ax=9%2F3-8%2F3\" Make 3 into a fraction with a denominator of 3
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\n" ); document.write( " \"4%2Ax-4%2Ax=1%2F3\" Combine the terms on the right side
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\n" ); document.write( " \"0%2Ax=1%2F3\" Now combine the terms on the left side.
\n" ); document.write( " \"0%2F1=1%2F3\" 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%28+500%2C+600%2C+-6%2C+5%2C+-10%2C+10%2C+%288-12%2Ax%29%2F3%2C+%283-4%2Ax%29%2F1+%29+\" graph of \"12%2Ax%2B3%2Ay=8\" (red) and \"4%2Ax%2B1%2Ay=3\" (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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