what is the value of x in the figure?

Those are vertical angles so both sides need to be equal.
2x+15 = 145
Subtract 15 from both sides:
2x = 130
Divide both sides by 2:
x = 65
Answer:
145 = 2x + 15
2x = 130
x = 65
145 and 2x + 15 are vertical angles and therefore congruent.