Question

Найдите значение упрощенного выражения: и второе, решите деление пожалуйста

Answer 1

Ответ:

$1) \frac{5a}{(a + {3}^{2} )} \times ( {a}^{2} - 9) = \frac{5 {a}^{3} - 45a }{a + 9} = \frac{5 \times ( - 2) {}^{3} - 45 \times ( - 2)}{ - 2 + 9} = \frac{ - 40 + 90}{7} = \frac{50}{7} = 7 \frac{1}{7}$

$2)1) \frac{ {x}^{2} + 10x + 25}{ {x}^{2} + 5x } \div \frac{ {x}^{2} - 25}{ {x}^{3} } = \frac{ {(x + 5)}^{2} }{x(x + 5)} \div \frac{(x - 5)(x + 5)}{ {x}^{3} } = \frac{ {(x + 5)}^{2} \times {x}^{3} }{x(x + 5)(x - 5)(x + 5)} = \frac{ {x}^{2} }{x - 5}$

$2)2) \frac{49 - 14x + {x}^{2} }{7 {x}^{2} - {x}^{3} } \div \frac{49 - {x}^{2} }{ {x}^{3} } = \frac{(7 - x) {}^{2} }{ {x}^{2} (7 - x)} \div \frac{(7 - x)(7 + x)}{ {x}^{3} } = \frac{ {(7 - x)}^{2} \times {x}^{3} }{ {x}^{2} (7 - x)(7 - x)(7 + x)} = \frac{x}{7 + x}$