Answer :
I will be using the substitution method
y=2x+5
y=x+4
____________
because y=y and they are the same,
2x+5=x+4
-5 -5
-------------
2x=x-1
-x -x
------------
x=-1
then plug in
y=2x+5
y=2(-1)+5
y=-2+5
y=3
____________
y=x+4
y=(-1)+4
y=3
the answers are the same, that is the check
y=2x+5
y=x+4
____________
because y=y and they are the same,
2x+5=x+4
-5 -5
-------------
2x=x-1
-x -x
------------
x=-1
then plug in
y=2x+5
y=2(-1)+5
y=-2+5
y=3
____________
y=x+4
y=(-1)+4
y=3
the answers are the same, that is the check