Answer:
x = 7.
Step-by-step explanation:
Because the angle is bisected we have the equation:
21 / 14 = (3x - 12) / 6 (By the Bisector of an Angle in a Triangle theorem).
14(3x - 12) = 6*21
42x - 168 = 126
42x = 294
x = 294/42
x = 7 answer.
