A system of equations means that both equations need to be true in the same time.
Since y is equal with 3x-7 and 2x+7 then those must be equal with eachother.
3x-7=2x+7
3x-2x=7+7
X=14
Now that we know x use any given equation of y and substitute x with 14
Y=3•14-7=35
Solution: x=14, y=35