In a cyclic quadrilateral we know that the exterior angle is equal to the interior opposite angle
So we get
∠BAD = ∠DCF = 75o
It can be written as
∠DCF = x = 75o
We get x = 75o
We know that the opposite angles of a cyclic quadrilateral is 180o
So we get
∠DCF + ∠DEF = 180o
By substituting the values
75o + ∠DEF = 180o
On further calculation
∠DEF = 180o – 75o
By subtraction
∠DEF = y = 105o
Therefore, the values of x and y is 75o and 105o.