<p>In this paper, fully actuated system approaches are utilized to synthesize feedback linearizable nonlinear systems. First, a simple transformation is introduced to convert feedback linearizable nonlinear systems into fully actuated system models for both single-input and multi-input scenarios. Once the fully actuated system model is established, a nonlinear state feedback controller can be derived to achieve a constant linear closed-loop system with an assignable eigenstructure. All degrees of freedom present in the closed-loop system can be leveraged to enhance overall system performance. In comparison to feedback linearization, the proposed method places greater emphasis on the control variables, making it more convenient to address control challenges in dynamic systems. Finally, two numerical examples are presented to illustrate the design procedure for both single-input and multi-input cases, and to validate the effectiveness of the proposed approach.</p>