How do you solve #2x + y = 5# and # x + y = 4#?

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Answer 1 · 2018-03-29T07:37:40

#color(blue)(x=1)# and #color(blue)(y=3)#

#2x+y=5\ \ \ \ [1]#

#x+y=4\ \ \ \ \ \ [2]#

Rearrange #[2]# so y is in terms of #x#:

#y=4-x \ \ \[3]#

Substitute #[3]# into #[1]#:

#2x+(4-x)=5#

#2x+4-x=5#

#x=5-4=1#

Substitute this result into #[2]#:

#1+y=4#

#y=4-1=3#

Result:

#color(blue)(x=1)# and #color(blue)(y=3)#