\[\boxed{\text{401\ (401).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[\textbf{а)}\ (x - 3)(y - 3) = 0\]
\[\textbf{б)}\ (x + 2)(y + 2) = 0\]
\[\textbf{в)}\ (y + 2)(y - 2) = 0\]
\[\textbf{г)}\ (x - 4)(x + 2) = 0\ \]