Question

решите подробно пожалуйста

Answer 1

$\frac{6c {d}^{2} }{ {c}^{2} - 81 {d}^{2} } \times \frac{c - 9d}{cd} = \\ \frac{6d}{(c - 9d)(c + 9d)} \times (c - 9d) = \\ \frac{6d}{c + 9d} = \frac{6 \times ( - 0.2)}{3 - 9 \times ( - 0.2)} = \\ \frac{ - 1.2}{4.8} = - \frac{1}{4} = - 0.25$