Answer:
x = 25
Explanation:
In the image shown you have correctly identified the angles as vertical. Vertical angles are equal. This means that the angle "4x - 25" is the same as the angle "75". we can write this as:
4x - 25 = 75
Add 25 to both sides
4x = 100
This means that 4 x's will make one hundred. If you divide 100 by four you get four equal parts that make 100. Divide both sides by 4.
x = 25