Step 1: Understanding the Concept:
Force between two parallel conductors: $F = \frac{\mu_0 I_1 I_2}{2\pi d}$.
Step 2: Detailed Explanation:
$F_{BA} = \frac{\mu_0 I \cdot I}{2\pi x}$ (attractive, since currents in same direction). $F_{CA} = \frac{\mu_0 (2I) \cdot I}{2\pi (2x)} = \frac{\mu_0 I^2}{2\pi x}$ (repulsive, since currents in opposite direction). So $F_{BA} = F_{CA}$ but opposite in direction, hence $F_1 = -F_2$.
Step 3: Final Answer:
$F_1 = -F_2$.