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-9x+20y=22

-5x+10y=10

 Jul 1, 2018
 #1
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This is actually a very easy question.

 

Multiply -5x+10y=10 by -2 because we want something common with the first equation and negative because we want to eliminate it later.

 

We get 10x-20y=-20

 

Then we cross out the 20y

 

And we are left with: -9x=22 and 10x=-20

 

Then we add them(both sides) and get x=2

 

And then we substitute it in whichever equation you want to

 

-9x+20y=22

-9(2)+20y=22

-18+20y=22

Add 18 on both sides

20y=40

Then divide 20 on both sides

y=2

 

So we get x=2 and y=2!

 

Then you can substitute them back into both equations and check your work but I don't have time so bye. Hope that helps!! 

 Jul 3, 2018

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