How do you solve x+y=6 and x-y=2?

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Answer 1 · 2018-03-11T10:00:14

#x=4#
#y=2#

#x+y=6|-y#
#x=6-y#

#color(red)(x)-y=2#
#color(red)(6-y)-y=2#
#6-2y=2|-6#
#-2y=-4|:(-2)#
#y=2#

#x+color(blue)(y)=6#
#x+color(blue)(2)=6|-2#
#x=4#

Answer 2 · 2018-03-11T10:00:19

#x = 4#

We can eliminate #y# from the equation by adding the two together, as #y + -y = y-y = 0#
We must also add the other terms.
#2x = 8#
#x = 4#

Answer 3 · 2018-03-11T10:03:59

#x= 4, y= 2#

#x+y=6#, and #x-y=2#
You can eliminate it or subtitute it.

A. Eliminate

#x+y=6#
#x-y=2#
______ -
#2y=4, y=2#
And it makes #x=4#

B. Subtitute

#x+y=6#
#y=6-x#

#x-y=x-(6-x)=2#

#2x-6=2#
#2x=8, x=4#
#x+y=4+y=6, y=2#