\[\boxed{\text{424\ (424).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[\textbf{а)}\ y = x + 1;\ \ y = x - 1:\ \]
\[(x - y + 1)(y - x + 1) = 0.\]
\[\textbf{б)}\ y = x^{2};\ \ y = - 2:\]
\[\left( y - x^{2} \right)(y + 2) = 0.\]