SOLUTION: 1. 3x=-5-x 2x+y=-5 2. 3x-5y=7 2x-y=-7 3. x-3y=1 3x-5y=-5

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Question 168738: 1.
3x=-5-x
2x+y=-5
2.
3x-5y=7
2x-y=-7
3.
x-3y=1
3x-5y=-5

Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!
# 1
Your first equation has two "x" variables. Is there a "y" term in the first equation?




# 2


Start with the given system of equations:



Multiply the both sides of the second equation by -5.


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 y terms cancel out.


Simplify.


Divide both sides by to isolate .


Reduce.


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


Now go back to the first equation.


Plug in .


Multiply.


Add to 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)





# 3



Start with the given system of equations:



Multiply the both sides of the first equation by -3.


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.


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


Now go back to the first equation.


Plug in .


Multiply.


Add to 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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