You can watch these episodes on platforms like Crunchyroll or Hulu.
Eren survives being eaten by a Titan and emerges from its carcass in Titan form. Shingeki no Kyojin Episode 9
Reiner makes a deal with Ymir to ensure Historia's safety if she joins them. Season 3, Episode 9: "Ruler of the Walls" You can watch these episodes on platforms like