Question

Избавьте от иррациональности

Answer 1

Объяснение:

$\frac{ \sqrt{14} }{ \sqrt{6} \times \sqrt{21}} = \sqrt{ \frac{14}{6 \times 21} } = \sqrt{ \frac{2 \times 7}{(2 \times 3) \times (3 \times 7)} } = \sqrt{ \frac{1}{ {3}^{2} } } = \frac{1}{3}$

$\frac{5 - a}{1 + \sqrt{5}} = \frac{(5 - a) \times (1 - \sqrt{5)} }{(1 + \sqrt{5}) \times (1 - \sqrt{5}) } = \frac{(5 - a) \times (1 - \sqrt{5}) }{ {1}^{2} - {( \sqrt{5}) }^{2} } = \frac{(5 - a) \times (1 - \sqrt{5}) }{ - 4}$

$\frac{1.5c}{ \sqrt{3} + c} = \frac{1.5c \times ( \sqrt{3} - c) }{( \sqrt{3} + c) \times ( \sqrt{3} - c)} = \frac{1.5c \times ( \sqrt{3} - c) }{3 - {c}^{2}}$