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How do you solve the following system: #2x-y=7, 2x +5y = 5 #?

1 Answer

Dec 22, 2015

#(x,y)=(3 1/3, -1/3)#

Explanation:

Given:
[1]#color(white)("XXX")2x-y=7#
[2]#color(white)("XXX")2x+5y=5#

Subtract [2] from[1]
[3]#color(white)("XXX")-6y=2#

Divide both sides by #(-6)# (and reduce the resulting fraction)
[4]#color(white)("XXX")y=-1/3#

Substitute #(-1/3)# for #y# in [1]
[5]#color(white)("XXX")2x-(-1/3)=7#

Subtract #1/3# from both sides
[6]#color(white)("XXX")2x=6 2/3#

Divide both sides by #2#
[7]#color(white)("XXX")x=3 1/3#

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