How do you solve #x+y=1# and #x-y=2 # using substitution?

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Answer 1 · 2016-04-11T13:51:57

(1.5, -0.5)

#x+y=1#
#x+y-y=1-y#
So #x=1-y#
Substitute this x-value into the second equation.

#(1-y) -y = 2#

#1-2y = 2#

#1-2y-1=2-1#

#-2y=1#

#(-2y)/-2=1/-2#

#y=-0.5#

Substitute this answer into the original formula

#x+(-0.5)=1#

#x+(-0.5)+(0.5)=1+(0.5)#

#x=1.5#

Check by substituting into the second formula.

#1.5-(-0.5)=2#

#2=2#