Help, I cant find the answer on this circle answer

Answer:
d.
Step-by-step explanation:
Apply the angle of intersecting secant theorem.
[tex] \frac{12x - 5 - 2x + 7}{2} = 6x + 19[/tex]
[tex] \frac{10x - 12}{2} = 6x + 19[/tex]
[tex]5x - 6 = 6x + 19[/tex]
[tex] - 6 = x + 19[/tex]
[tex]x = 13[/tex]
Plug 13 into Arc SW.
[tex](12)(13) - 5 = 151[/tex]