For angle x, you must use the fact that the angle at the centre of a circle is twice the angle at the circumference.
So the angle opposite x is 140, so the angle at the centre is 360 - 140 = 220. So 2x = 220, so x = 110
The angle sum of a quadrilateral is 360, so
y + 140 + 110 + 62 = 360
y +...