i need help with this question (answer choices 15, 5, and 12)

Answer:
x = 15
Step-by-step explanation:
the opposite angles of a cyclic quadrilateral sum to 180° , then
6x + 20 + 3x + 25 = 180 , that is
9x + 45 = 180 ( subtract 45 from both sides )
9x = 135 ( divide both sides by 9 )
x = 15