Given the floor system shown in Fig. P$7\mathrm{.}3.f_c^{\text{'}}=315$MPa,$f_y=420$MPa for the longitudinal steel and $f_y=280$MPa for the transverse steel :

a$)$ Design the spandrel beam between columns A$1$ and B$1$ for bending, shear, and torsion. Check all of the appropriate ACI Code requirements for strength, minimum reinforcement area, and reinforcement spacing are satisfied.

$($b$)$ Design the spandrel beam between columns A$1$ and $A2$ for bending, shear, and torsion. Check that all of the appropriate ACI Code requirements for strength, minimum reinforcement area, and reinforcement spacing are satisfied.