document.write( "Question 1130654: Use elimination to solve the system. (Simplify your answer completely. If the system is dependent, enter a general solution in terms of x and y.)\r
\n" ); document.write( "\n" ); document.write( "x − y = 9
\n" ); document.write( "1/3 x = 1/3 y + 3
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Algebra.Com's Answer #747292 by MathLover1(20850)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "\"x+-y+=+9\"
\n" ); document.write( "\"%281%2F3%29+x+=+%281%2F3%29+y+%2B+3\"
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\n" ); document.write( "\n" ); document.write( "\"x+-y+=+9\"
\n" ); document.write( "\"%281%2F3%29+x+-%281%2F3%29+y=+3\"\r
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Solved by pluggable solver: Solving a System of Linear Equations by Elimination/Addition

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\n" ); document.write( " \"%281%2F3%29%2Ax%2B%28-1%2F3%29%2Ay=3\" Start with the second equation
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\n" ); document.write( " \"3%28%281%2F3%29%2Ax%2B%28-1%2F3%29%2Ay%29=%283%29%2A%283%29\" Multiply both sides by the LCD 3
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\n" ); document.write( " \"1%2Ax%2B-1%2Ay=9\" Distribute and simplify
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\n" ); document.write( " Lets start with the given system of linear equations
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\n" ); document.write( " \"1%2Ax-1%2Ay=9\"
\n" ); document.write( " \"1%2Ax-1%2Ay=9\"
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\n" ); document.write( " In order to solve for one variable, we must eliminate the other variable. So if we wanted to solve for y, we would have to eliminate x (or vice versa).
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\n" ); document.write( " So lets eliminate x. In order to do that, we need to have both x coefficients that are equal but have opposite signs (for instance 2 and -2 are equal but have opposite signs). This way they will add to zero.
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\n" ); document.write( " So to make the x coefficients equal but opposite, we need to multiply both x coefficients by some number to get them to an equal number. So if we wanted to get 1 and 1 to some equal number, we could try to get them to the LCM.
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\n" ); document.write( " Since the LCM of 1 and 1 is 1, we need to multiply both sides of the top equation by 1 and multiply both sides of the bottom equation by -1 like this:
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\n" ); document.write( " \"1%2A%281%2Ax-1%2Ay%29=%289%29%2A1\" Multiply the top equation (both sides) by 1
\n" ); document.write( " \"-1%2A%281%2Ax-1%2Ay%29=%289%29%2A-1\" Multiply the bottom equation (both sides) by -1
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\n" ); document.write( " So after multiplying we get this:
\n" ); document.write( " \"1%2Ax-1%2Ay=9\"
\n" ); document.write( " \"-1%2Ax%2B1%2Ay=-9\"
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\n" ); document.write( " Notice how 1 and -1 add to zero, -1 and 1 add to zero, 9 and -9 and to zero (ie \"1%2B-1=0\") \"-1%2B1=0\", and \"9%2B-9=0\")
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\n" ); document.write( " So we're left with
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\n" ); document.write( " \"0=0\"
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\n" ); document.write( " which means any x or y value will satisfy the system of equations. So there are an infinite number of solutions
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\n" ); document.write( " So this system is dependent
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