Critique my proof of: Suppose A, B, and C are sets. Then $A \cap (B \setminus C) = (A \cap B) \setminus C$.

Here is another way to approach it for the sake of curiosity.

According to the properties and definitions involved, we can conclude that

\begin{align*} A\cap(B\backslash C) & = A\cap (B\cap C^{c})\\\\ & = (A\cap B)\cap C^{c}\\\\ & = (A\cap B)\backslash C \end{align*}

and we are done.

As to your proof, it sounds good.

Hopefully this helps!