Final answer:
Juan may be able to set aside the contract if he can prove that it was a result of undue influence. Evidence of a confidential or fiduciary relationship can support this claim. Consulting with a contract law lawyer is crucial in navigating the legal process.
Step-by-step explanation:
Undue influence can occur when one party exerts an unfair amount of pressure or power over another party, resulting in an unbalanced and unfair contract. In this case, Juan is an elderly man who is dependent on his nephew, Samuel, for support.
Samuel threatens to withdraw his support unless Juan agrees to transfer a tract of land for a price significantly below its market value. This can be considered undue influence.
Juan may be able to set aside this contract if he can prove that the transfer of the land was a result of Samuel's undue influence. One way to prove this is by showing evidence of a confidential or fiduciary relationship between Juan and Samuel, which gives Samuel a position of power and control over Juan.
Additionally, Juan can argue that the terms of the contract are unfair and that he did not have the ability to negotiate or understand the consequences of his decision.
It's important for Juan to consult with a lawyer who specializes in contract law to assess the specific details of his case and determine the best course of action. The lawyer can provide guidance on how to gather evidence, assess the strength of the claim of undue influence, and help Juan navigate the legal process to potentially set aside the contract.