\[\boxed{\text{98.\ }\text{ОК\ ГДЗ\ -\ домашка\ на\ 5}}\]
\[\textbf{а)}\ Нули\ функции:x = 3,1.\]
\[y < 0:\ - 6 \leq x < - 3;\ \ \]
\[\ 3,1 < x < 6.\ \]
\[y > 0:\ - 3 < x < 3,1.\]
\[возрастает:\lbrack - 6; - 3);\ \ ( - 3;0).\]
\[убывает:(0;6).\]
\[D(f) = \lbrack - 6;\ - 3) \cup ( - 3;6);\]
\[E(f) = ( - 5;4\rbrack.\]
\[\textbf{б)}\ Нули\ функции:x = - 7;\]
\[x = - 1;x = 1;x = 3.\]
\[y < 0:( - 7;0);(1;3).\]
\[y > 0:\lbrack - 8; - 7);(0;1);(3;4\rbrack.\]
\[возрастает:( - 4;0);(2;4\rbrack.\]
\[убывает:\lbrack - 8; - 4);(0;2).\]
\[D(f) = \lbrack - 8;4\rbrack;\ \]
\[E(f) = \lbrack - 5;7\rbrack.\]