Answer:
y = 12
Step-by-step explanation:
[tex]\text{If}\ \overrightarrow{BD}\ \text{is the angle bisector of}\ \angle ABC,\ \text{then we have the equation:}\\\\3y+6=5y-18\qquad\text{subtract 6 from both sides}\\3y=5y-24\qquad\text{subtract 5y from both sides}\\-2y=-24\qquad\text{divide both sides by (-2)}\\\boxed{y=12}[/tex]
