\[\boxed{\text{156\ (156).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[\boxed{\text{156.}\text{\ }\text{ОК\ ГДЗ\ -\ домашка\ на\ 5}}\]
\[\textbf{а)}\ y = (x - 2)(x + 4)\]
\[\textbf{б)}\ y = - x(x + 5)\ \]