F_a , F_b = resultant forces of bending stresses acting on the bottom 2 x 12 board

From the bending stress distribution, we can determine the resultant force acting on the 2 x 12 board, both on the left-hand side (a) and the right-hand side (b). These resultant forces act in the direction of the beam's longitudinal axis (i.e., the x direction).

Consequently, the magnitude of resultant force F_b will be greater than F_a.