Answer:
x = 5
Step-by-step explanation:
According to triangle angle bisector theorem, the ray divides the opposites side of the triangle into segments that are proportional to the other two sides.
So,
[tex]\frac{x-1}{x-2} = \frac{12}{9}\\\\\frac{x-1}{x-2} = \frac{4}{3}\\\\3(x-1) = 4(x-2)\\\\3x - 3 = 4x - 8\\\\4x - 3x = -3 +8 \\\\x = 5[/tex]