Final answer:
The correct verb form to fill in the blank in the sentence is "encuentro".
Step-by-step explanation:
The correct verb form to fill in the blank in the sentence "Necesito mi tarea de matemáticas, y no la (yo)" is encuentro, which is the first-person singular form of the verb "encontrar" (to find). So the correct sentence would be: "Necesito mi tarea de matemáticas, y no la encuentro."
Learn more about Verb forms in Spanish