1) Persuadable 2) Persuasible 3) Suasible 4) Susceptible 
• (a.) Capable of being confuted and disproved by argument; refutable. • (a.) Capable of being convinced or won over.
Con·vin'ci·ble adjective 1. Capable of being convinced or won over. 2. Capable of being confuted and disproved by argument; refutable. [ Obsolete] Sir T. Browne. 
[adj] - being susceptible to persuasion
convincible 1. Being susceptible to persuasion. 2. Capable of being convinced by someone of the truth of a statement, proposition, situation, etc.
persuadable adjective being susceptible to persuasion