[Discrete Math] Properties of Sets Proofs

Can someone please look this over to see if the proof is accurate? In the second part of the proof, for the steps marked review, I just guessed the steps to try to make it into the form I wanted, but I don't know if that's valid. It wouldn't be the distributive property, and I am not really sure how to justify that. Any help provided would be appreciated. Thank you

https://preview.redd.it/kh7s46lp2j0e1.png?width=945&format=png&auto=webp&s=dacd48309d459fddb85a0699b2163e93ba2df3c3