How do you solve the following system: #2x-6y=-12 , 2x + y = 8 #?

1 Answer
Alan P.
Feb 4, 2016

#(x,y)=(18/7,20/7)#

Explanation:

Given:
[1]#color(white)("XXX")2x-6y=-12#
[2]#color(white)("XXX")2x+y=8#

Subtract equation [1] from equation [2] to get:
[3]#color(white)("XXX")7y=20#

Divide both sides of equation [3] by #7#:
[4]#color(white)("XXX")y=20/7#

Substitute #20/7#, the value given for #y# in equation [4], for #y# in equation [2]
[5]#color(white)("XXX")2x+20/7=8#

Subtract #20/7# from both sides of equation [5] and simplify the right side
[6]#color(white)("XXX")2x=8-20/7 = 56/7-20/7 = 36/7#

Divide both sides of equation [6] by #2#
#color(white)("XXX")x=18/7#

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