slope of side WX = (4-2) / (2- -5) = 2/7
line ZY will have the same slope as its opposite line WX
so 2/7 =( y - -3) / (x - -7) where x and y are the coordinates of point y.
2/7 = (y + 3)/(x + 7)
2x - 7y = 7
slope of WZ = 5/2
slope of XY 5/2 also
5/2 = ( y -4) / x - 2) = 5/2
5x - 2y = 2
2x - 7y = 7
solving these 2 equations we get x = 0 and y = -1
Answer coordinates of y are (0, -1)