Question

Помогите пожалуйста решить

Answer 1

Ответ:

$\frac{5}{b - 3} + \frac{1}{ {b}^{} + 3} - \frac{6}{9 - {b}^{2} } = \frac{5( {b}^{} + 3) + ({b}^{} - 3) + 6 }{ ({b}^{} - 3)( {b}^{} + 3) } = \frac{5 {b}^{} + 15 + {b}^{} - 3 + 6}{( {b}^{} - 3)( {b}^{} + 3)} = \frac{6 {b}^{} + 18 }{( {b}^{} - 3)( {b}^{} + 3)} = \frac{6( {b}^{} + 3) }{( {b}^{} - 3)( {b}^{} + 3)} = \frac{6}{ {b}^{} - 3} = \frac{6}{2 \frac{2}{7} - 3} = \frac{6}{ - \frac{5}{7} } = 6 \div ( - \frac{5}{7} ) = - \frac{6 \times 7}{5} = - \frac{42}{5} = - 8.4$