\[\boxed{\text{578\ (578).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[\textbf{а)}\ x^{4} - 5 - x^{2} + 12x =\]
\[= - 5 + 12x - x^{2} + x^{4}\]
\[\textbf{б)}\ 2y + y^{3} - y^{2} + 1 =\]
\[= 1 + 2y - y^{2} + y^{3}\]