Step-by-step explanation:
I am not sure this is a square.
this could be a rectangle.
to be safe, I am following that path.
in a rectangle opposite sides are of equal length.
that means
y - 1 = 2y - 7
y = 2y - 6
0 = y - 6
y = 6
3x - 4 = 3y - 13
3x - 4 = 3×6 - 13
3x - 4 = 18 - 13 = 5
3x = 9
x = 3
as it turns out, it is a square, so we could have used every side expression to be equal with every other side expression, but better safe than sorry ...