Answer: x = 84°.
Step-by-step explanation: The sum of interior angles of a quadrilateral is equal to 360°. We are given three of the interior angles and asked to find the remaining angle. To do this, we can add the three given angles and subtract the sum from 360°. 53° + 125° + 98° = 276°. 360° - 276° = 84°. Thus, x = 84°.