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How do you solve the system #x - 3y = -3#, #x + 3y = 9#?

1 Answer

Nov 21, 2015

#(3,2)#

Explanation:

We can use linear combination.

Add the two equations together (notice that the #y# terms will cancel out):

#x-3y=-3#
#x+3y=9#
#2x=6#

Therefore, if we divide both sides by #2#, we see that #x=3#. We can then plug #3# back into either equation for #x# in order to solve for #y#.

(Plugging into the first equation:)
#3-3y=-3#
#-3y=-6#
#y=2#

Since #x=3# and #y=2#, we can write our answers in an ordered pair: #(3,2)#.

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