We know that a triangle adds up to 180 degrees.
Here, 130 is a vertical angle so on the opposite side the triangle makes, it is also 130. Then we could add 130 to 25
130 + 25 = 155
Now let’s subtract this from 180.
180 - 155 = 25.
X is a supplementary angle to 25 so subtract 25 from 180.
180 - 25 = 155
X = 155.