How do you solve #-3x+y=-4# and #2x+y=1# using substitution?

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Answer 1 · 2016-03-04T16:56:56

The solution for the system of equations is:
#color(green)(x=1#
#color(green)(y=-1#

#-3x+y=-4#.......equation #(1)#

#2x +y=1#

#color(green)(y=1-2x#..................equation #(2)#

Substituting equation #(2)# in #(1)#:

#-3x+y=-4#

#-3x+color(green)(1-2x)=-4#

#-5x +1=-4#

#-5x =-4-1#

#-5x =-5#

#x =(-5)/(-5)#

#color(green)(x=1#

Finding #y# from equation #2#:
#y=1-2x#

#y=1-2 xx 1#

#y=1-2 #

#color(green)(y=-1#