A kite consists of two isosceles triangles ABD and BCD joined at their common base BD.
So AB=AD and BC=CD (equal lengths), therefore 5x-y=y+2 and 3x+y=4y-3x.
So 5x-2y=2 and 6x=3y, so y=2x, which we can substitute into the other equation: 5x-4x=2, so x=2 and y=4.
AB=AD=5x-y or y+2=6, BC=CD=3x+y or 4y-3x=10.
