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What is the solution to the system of linear equations?

−9x+4y=55

−11x+7y=82

 Aug 31, 2018
 #1
avatar+98130 
+1

−9x+4y=55

−11x+7y=82

 

Multiply the top equation  through by  7  and the bottom equation through by  -4   and we get

 

-63x + 28y  =  385     (1)

44x  - 28y   = -328     (2)

 

Add (1)  and (2)  and we have

 

-19x   = 57    divide both sides by  -19

x  = -3

 

And using   -9x + 4y  =  55   we can find y  as

 

-9(-3) + 4y  = 55

27 + 4y  = 55   subtract 27 from both sides

4y  = 28   divide both sides by 4

y  =  7

 

So  ....(x,y)  = ( -3, 7)

 

 

cool cool cool

 Aug 31, 2018
 #2
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+1

THANK YOUUU!!

 Aug 31, 2018

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