How do you solve #2x + y = 7# and #4x - y = 23 #?

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Answer 1 · 2016-03-06T09:42:15

#x,y=5,-3#

#color(blue)(1) )color(blue)(2x+y=7#

#color(blue)(2))color(blue)(4x-y=23#

We can eliminate #y# from the first equation by #-y# in the second equation

Add both of the equations

#rarr(2x+y=7)+(4x-y=23)#

#rarr6x=30#

#color(green)(rArrx=30/6=5#

Now substitute the value of #x# to the first equation

#rarr2(5)+y=7#

#rarr10+y=7#

#color(green)(rArry=7-10=-3#