How do you find the solution of the system of equations #3x - y = 10# and #-x + y = -4#?

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Answer 1 · 2015-05-02T07:55:23

We can add the two equations to eliminate #y#

Adding the 2 equations will give us:

#(3x - y) +(-x + y) = 10 - 4 #

#3x - cancel(y) -x + cancel(y) = 6#

#2x= 6#
#color(blue)(x = 3)#

Substituting this value of #x# in the first equation we get #y# :

we are given:
# 3x - y = 10#

# 3.3- y = 10#
# 9 - y= 10 #
# -1 = y#

#color(blue)(y=-1)#

The solution to these system of equations is:

#color(blue)(x = 3 , y = -1#