Answer:
x = 7
Step-by-step explanation:
Since the segment is an angle bisector, the sides are in the ratio
[tex]\frac{14}{21}[/tex] = [tex]\frac{6}{3x-12}[/tex] ( cross- multiply )
14(3x - 12) = 126 ( divide both sides by 14 )
3x - 12 = 9 ( add 12 to both sides )
3x = 21 ( divide both sides by 3 )
x = 7