Question

(30 балллв) Умоляю вас помогите мне СРОЧНО ПО ДЕЙСТВИЯМ

Answer 1

1)
$( \frac{a - 2}{a + 2} - \frac{a + 2}{a - 2} ) \div \frac{12a {}^{2} }{4 - a {}^{2} } = \frac{2}{3a} \\ \\ 1) \: \: \frac{a - 2}{a + 2} - \frac{a + 2}{a - 2} = \frac{(a - 2)(a - 2) - (a + 2)(a + 2)}{(a + 2)(a - 2)} = \frac{a {}^{2} - 4a + 4 - a {}^{2} - 4a - 4}{(a + 2)(a - 2)} = \frac{ - 8a}{(a + 2)(a - 2)} \\ \\ \\ 2) \frac{ - 8a\times (2 - a)(2 + a)}{(a + 2)(a - 2) \times12a {}^{2} } = \frac{ - 2 \times (2 - a)}{3a \times(a - 2) } = \frac{2(a - 2)}{3a(a - 2)} = \frac{2}{3a}$

2)
$( \frac{3m}{m + 5} - \frac{8m}{m {}^{2} + 10m + 25} ) \div \frac{3m + 7}{m {}^{2} - 25} + \frac{5m - 25}{m + 5} = m - 5 \\ \\ \\ 1) \frac{3m}{m + 5} - \frac{8m}{(m + 5) {}^{2} } = \frac{3m(m + 5) - 8m}{(m + 5) {}^{2} } = \frac{3m {}^{2} + 15m - 8m }{(m + 5) {}^{2} } = \frac{3m {}^{2} + 7m }{(m + 5) {}^{2} } \\ \\ \\ 2) \: \: \frac{m(3m + 7) \times (m - 5)(m + 5)}{(m + 5)(m + 5) \times (3m + 7)} = \frac{m(m - 5) }{m + 5} \\ \\ \\ 3) \frac{m(m - 5)}{m + 5} + \frac{5(m - 5)}{m + 5} = \frac{m {}^{2} - 5m + 5m - 25 }{m + 5} = \frac{m {}^{2} - 25}{m + 5} = \frac{(m - 5)(m + 5)}{m + 5} = m - 5$

Надеюсь всё понятно!