Bending stress in a beam with overhang

Constructing the shear diagram

Considering the segment
from x = 8.6 m to x = 12 m

 area under shear
     diagram = -34.68 kN-m
 concentrated
   moments =     0.00 kN-m
 change in bending
     moment = -34.68 kN-m

    at x = 8.6 m,  M =   +34.68 kN-m
 change in bending
          moment    =   -34.68 kN-m
    at x = 12 m,   M =      0.00 kN-m