Question

Плиз даю 100 Балов помогите ​

Answer 1

$( \frac{ {b}^{2} + 16}{ {b}^{2} - 16 } + \frac{b}{b + 4} + \frac{b}{4 - b} ) \div \frac{ {b}^{2} - 4b}{(b + 4) {}^{2} } = \\ = ( \frac{ {b}^{2} + 16}{ ({b} - 4)(b + 4) } + \frac{b}{b + 4} - \frac{b}{b - 4} ) \div \frac{ {b}(b - 4)}{(b + 4) {}^{2} } = \\ = \frac{ {b}^{2} + 16 + b(b - 4) - b (b + 4)}{(b - 4)(b + 4)} \times \frac{(b + 4) {}^{2} }{b(b - 4)} = \\ = \frac{ {b}^{2} + 16 + b {}^{2} - 4b - {b}^{2} - 4b }{(b - 4)} \times \frac{b + 4}{b(b - 4)} = \\ = \frac{ {b}^{2} - 8b + 16}{b - 4} \times \frac{b + 4}{b(b - 4)} = \frac{(b - 4) {}^{2} }{b - 4} \times \frac{b + 4}{b(b - 4)} = \\ = \frac{b + 4}{b}$