Question

Решите пожалуйста 3 задания!

Answer 1

$(v - \frac{6v}{v +1 } ) \div \frac{v - 5}{v + 1} = \frac{ {v}^{2} + v - 6v }{v + 1} \times \frac{v + 1}{v - 5} = \frac{( {v}^{2} - 5v)(v + 1)}{(v + 1)(v - 5)} = \frac{v(v - 5)}{v - 5} = v. \\ \\ ( \frac{a + 3}{a - 3} + \frac{a - 3}{a + 3} ) \div \frac{3 {a}^{2} + 27 }{9 - {a}^{2} } = \frac{ {a}^{2} + 6a + 9 + {a}^{2} - 6a + 9 }{ {a}^{2} - 9 } \times \frac{ - ( {a}^{2} - 9) }{3( {a}^{2} + 9)} = - \frac{(2 {a}^{2} + 18)( {a}^{2} - 9) }{3( {a}^{2} - 9)( {a}^{2} + 9)} = - \frac{2( {a}^{2} + 9) }{3( {a}^{2} + 9)} = - \frac{2}{3} .$