SOLUTION: -9=x-3y -2x+6=6y

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Question 147493: -9=x-3y
-2x+6=6y

Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!

Start with the first equation.


Add to both sides.


Subtract from both sides.


Add to both sides.


----------------------------

Start with the second equation.


Subtract from both sides.


Subtract from both sides.


So we have the system of equations:





Multiply the both sides of the first equation by 2.


Distribute and multiply.


Multiply the both sides of the second equation by -1.


Distribute and multiply.


So we have the new system of equations:



Now add the equations together. You can do this by simply adding the two left sides and the two right sides separately like this:





Group like terms.


Combine like terms. Notice how the x terms cancel out.


Simplify.


Divide both sides by to isolate .


Reduce.


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Now go back to the first equation.


Plug in .


Multiply.


Subtract from both sides.


Combine like terms on the right side.


Divide both sides by to isolate .


Reduce.


So our answer is and .


Which form the ordered pair .


This means that the system is consistent and independent.


Notice when we graph the equations, we see that they intersect at . So this visually verifies our answer.


Graph of (red) and (green)


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