Question

38.9. а+ 2с = 7
найдите значение дробно-рационального выражения​

Answer 1

1)

$\frac{3a + 6c}{(2c + a) {}^{2} } = \frac{3(2c + a)}{ {(2c + a)}^{2} } = \frac{3}{2c + a} = \frac{3}{7}$

2)

$\frac{a + 2c}{2(2c + a) {}^{2} } = \frac{1}{2(2c + a)} = \frac{1}{2 \times 7} = \frac{1}{14}$

3)

$\frac{a + 2c}{(2c + a) {}^{3} } = \frac{1}{(a + 2c) {}^{2} } = \frac{1}{ {7}^{2} } = \frac{1}{49}$

4)

$\frac{(2c - a) \times 4}{(4 {c}^{2} - {a}^{2}) } = \frac{(2c - a) \times 4}{(2c - a)(2c + a)} = \frac{4}{2c + a} = \frac{4}{7}$