Why does hercules defeat hydra?

Hercules upon reaching the beast's lair, covered his nostril and mouth to escape from the poison fumes.He fought with the Hydra using bow & Arrow intially and also sword. But for each head he slew two more grew. He didn't know initially that the center head was the immortal one which when slew will not grow back.

Explanation:

As soon as Hercules cut off one head, Iolaus would cauterise the wound with a flaming torch so that nothing could grow to replace it. After removing the Hydra immortal head, Hercules buried it under a large rock. Then he collected the monster's poisonous blood.

Explanation: In the canonical Hydra myth, the monster is killed by Heracles (Hercules) as the second of his Twelve Labors. According to Hesiod, the Hydra was the offspring of Typhon and Echidna. It had poisonous breath and blood so virulent that even its scent was deadly.

a governess was mean to her.

explanation:

must repent and believe in god.

or the book

journey across time - chapter 10 "the rise of christianity"