Geometry

According to the laws of geometry, 

Angle B is one half of arc AC

$(4x-3.5)\cdot2=4x+17$

$8x-7=4x+17$

$4x=24$

$x=6$

Plugging this into 4x + 17, we get:

$4\cdot6+17=\boxed{41}$

I hope this helped,

Gavin