Constant evolution in integrated circuit technology has led to an increase in digital chip switching speed. There is thus growing interest in inductance associated with signal lines. In this study, for a three coupled-line distributed system, it is demonstrated that crosstalk voltages observed at their termination result from output modal voltage combinations generated when a mode propagates under particular input configurations. Crosstalk voltages were also found to be equal to the additivity of the electric and magnetic effects, both taken independently. Those demonstrations are realized because of a decoupling technique allowing the coupled-line system description as only an isolated line system. This decoupled system propagates the considered mode and depends on effective electrical parameters.