document.write( "Question 93526: -2x+3y=14
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Algebra.Com's Answer #68113 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
I'm assuming you want to solve the system right?\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( " \"-2%2Ax%2B3%2Ay=14\"
\n" ); document.write( " \"1%2Ax%2B2%2Ay=7\"
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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=14%2B2%2Ax\"Add \"2%2Ax\" to both sides
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\n" ); document.write( " \"y=%2814%2B2%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=14%2F3%2B%282%2F3%29%2Ax\" Now we've fully isolated y
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\n" ); document.write( " Since y equals \"14%2F3%2B%282%2F3%29%2Ax\" we can substitute the expression \"14%2F3%2B%282%2F3%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( " \"1%2Ax%2B2%2Ahighlight%28%2814%2F3%2B%282%2F3%29%2Ax%29%29=7\" Replace y with \"14%2F3%2B%282%2F3%29%2Ax\". Since this eliminates y, we can now solve for x.
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\n" ); document.write( " \"1%2Ax%2B2%2A%2814%2F3%29%2B2%282%2F3%29x=7\" Distribute 2 to \"14%2F3%2B%282%2F3%29%2Ax\"
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\n" ); document.write( " \"1%2Ax%2B28%2F3%2B%284%2F3%29%2Ax=7\" Multiply
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\n" ); document.write( " \"1%2Ax%2B28%2F3%2B%284%2F3%29%2Ax=7\" Reduce any fractions
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\n" ); document.write( " \"1%2Ax%2B%284%2F3%29%2Ax=7-28%2F3\" Subtract \"28%2F3\" from both sides
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\n" ); document.write( " \"1%2Ax%2B%284%2F3%29%2Ax=21%2F3-28%2F3\" Make 7 into a fraction with a denominator of 3
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\n" ); document.write( " \"1%2Ax%2B%284%2F3%29%2Ax=-7%2F3\" Combine the terms on the right side
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\n" ); document.write( " \"%283%2F3%29%2Ax%2B%284%2F3%29x=-7%2F3\" Make 1 into a fraction with a denominator of 3
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\n" ); document.write( " \"%287%2F3%29%2Ax=-7%2F3\" Now combine the terms on the left side.
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\n" ); document.write( " \"cross%28%283%2F7%29%287%2F3%29%29x=%28-7%2F3%29%283%2F7%29\" Multiply both sides by \"3%2F7\". This will cancel out \"7%2F3\" and isolate x
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\n" ); document.write( " So when we multiply \"-7%2F3\" and \"3%2F7\" (and simplify) we get
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\n" ); document.write( " \"x=-1\" <---------------------------------One answer
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\n" ); document.write( " Now that we know that \"x=-1\", lets substitute that in for x to solve for y
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\n" ); document.write( " \"1%28-1%29%2B2%2Ay=7\" Plug in \"x=-1\" into the 2nd equation
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\n" ); document.write( " \"-1%2B2%2Ay=7\" Multiply
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\n" ); document.write( " \"2%2Ay=7%2B1\"Add \"1\" to both sides
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\n" ); document.write( " \"2%2Ay=8\" Combine the terms on the right side
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\n" ); document.write( " \"cross%28%281%2F2%29%282%29%29%2Ay=%288%2F1%29%281%2F2%29\" Multiply both sides by \"1%2F2\". This will cancel out 2 on the left side.
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\n" ); document.write( " \"y=8%2F2\" Multiply the terms on the right side
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\n" ); document.write( " \"y=4\" Reduce
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\n" ); document.write( " So this is the other answer
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\n" ); document.write( " \"y=4\"<---------------------------------Other answer
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\n" ); document.write( " So our solution is
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\n" ); document.write( " \"x=-1\" and \"y=4\"
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\n" ); document.write( " which can also look like
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\n" ); document.write( " (\"-1\",\"4\")
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\n" ); document.write( " Notice if we graph the equations (if you need help with graphing, check out this solver)
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\n" ); document.write( " \"-2%2Ax%2B3%2Ay=14\"
\n" ); document.write( " \"1%2Ax%2B2%2Ay=7\"
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\n" ); document.write( " we get
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\n" ); document.write( " graph of \"-2%2Ax%2B3%2Ay=14\" (red) and \"1%2Ax%2B2%2Ay=7\" (green) (hint: you may have to solve for y to graph these) intersecting at the blue circle.
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\n" ); document.write( " and we can see that the two equations intersect at (\"-1\",\"4\"). This verifies our answer.
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\n" ); document.write( " Check:
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\n" ); document.write( " Plug in (\"-1\",\"4\") into the system of equations
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\n" ); document.write( " Let \"x=-1\" and \"y=4\". Now plug those values into the equation \"-2%2Ax%2B3%2Ay=14\"
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\n" ); document.write( " \"-2%2A%28-1%29%2B3%2A%284%29=14\" Plug in \"x=-1\" and \"y=4\"
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\n" ); document.write( " \"2%2B12=14\" Multiply
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\n" ); document.write( " \"14=14\" Add
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\n" ); document.write( " \"14=14\" Reduce. Since this equation is true the solution works.
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\n" ); document.write( " So the solution (\"-1\",\"4\") satisfies \"-2%2Ax%2B3%2Ay=14\"
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\n" ); document.write( " Let \"x=-1\" and \"y=4\". Now plug those values into the equation \"1%2Ax%2B2%2Ay=7\"
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\n" ); document.write( " \"1%2A%28-1%29%2B2%2A%284%29=7\" Plug in \"x=-1\" and \"y=4\"
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\n" ); document.write( " \"-1%2B8=7\" Multiply
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\n" ); document.write( " \"7=7\" Add
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\n" ); document.write( " \"7=7\" Reduce. Since this equation is true the solution works.
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\n" ); document.write( " So the solution (\"-1\",\"4\") satisfies \"1%2Ax%2B2%2Ay=7\"
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\n" ); document.write( " Since the solution (\"-1\",\"4\") satisfies the system of equations
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\n" ); document.write( " \"-2%2Ax%2B3%2Ay=14\"
\n" ); document.write( " \"1%2Ax%2B2%2Ay=7\"
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\n" ); document.write( " this verifies our answer.
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