Помогите пожалуйста не могу даю 35 баллов , СПАСИБО ЗА РАНЕЕ

Решите задачу:

$\frac{3a}{ {b}^{2} } \times \frac{ab + {b}^{2} }{9} = \\ = \frac{3a}{b \times b} \times \frac{b(a + b)}{3 \times 3} = \\ = \frac{a(a + b)}{3b}$
$( {x}^{2} - 4) \times \frac{2x}{(x + 2) ^{2} } = \\ = (x - 2)(x + 2) \times \frac{2x}{(x + 2) ^{2} } = \\ = \frac{2x(x - 2) }{x + 2}$
$\frac{6a}{ {x}^{2} - x } \times \frac{2x - 2}{3ax} = \\ = \frac{2 \times 3a \times 2(x - 1)}{x(x - 1) \times 3a \times x} = \\ = \frac{4}{ {x}^{2} }$
$\frac{ {x}^{2} - 16 }{ {x}^{3} - 3 {x}^{2} } \times \frac{ {x}^{2} - 9 }{ {x}^{2} + 4x } = \\ = \frac{(x - 4)(x + 4)(x - 3)(x + 3)}{ {x}^{2}(x - 3)x(x + 4) } =\\ = \frac{(x - 4)(x + 3)}{ {x}^{3} }$