Find the value of x.
6
14
8
0
21
x = [ ? ]
3x-12

Answer: 7
Step-by-step explanation:
By the angle bisector theorem,
[tex]\frac{21}{14}=\frac{3x-12}{6}\\21(6)=14(3x-12)\\126=14(3x-12)\\9=3x-12\\21=3x\\x=\boxed{7}[/tex]