Answer-
The value of x is 55°.
Solution-
In the given attachment, ABC is a triangle.
We know that in any triangle, the sum of measurement of all the 3 angles is 180°.
Hence,


Given that,
m∠A = x°
m∠B = 75°
m∠C = 50°
Putting the values,



Therefore, the value of x is 55°.