Question

Буду очень благодарен за помощь.

Answer 1

Ответ:

1)

а)

$\sqrt{ \frac{49}{16} } - 5 \times 1.2 = \frac{7}{4} - 6 = 1.75 - 6 = - 4.25$

б)

$\sqrt{81 \times 2} \times \sqrt{9 \times 2} = 9 \sqrt{2} \times 3 \sqrt{2} = 9 \times 3 \times 2 = 54$

в)

$\sqrt{(82 - 18)(82 + 18)} = \sqrt{64 \times 100 } = 8 \times 10 = 80$

г)

$( { \sqrt{2}) }^{2} - 2 \sqrt{2} \times \sqrt{8} + ( \sqrt{8} ) {}^{2} = 2 - 2 \times \sqrt{16} + 8 = 2 - 2 \times 4 + 8 = 2 - 8 + 8 = \\ = 2$

2)

а)

$5 \sqrt{12} \times \sqrt{3} - 5 \sqrt{12} \times 3 \sqrt{27} = 5 \sqrt{36} - 5 \sqrt{4 \times 3} \times 3 \sqrt{9 \times 3} = \\ 5 \times 6 - 5 \times 2 \sqrt{3} \times 3 \times 3 \sqrt{3} = 30 - 15 \times 6 \times 3 = \\ = 30 - 270 = - 240$

б)

$\sqrt{50 \times 0.08} = \sqrt{25 \times 2 \times 0.04 \times 2} = 5 \times 0.2 \times 2 = 2$

в)

$\sqrt{72} \div \sqrt{2} = \sqrt{2 \times 36} \div \sqrt{2} = 6$

г)

$\sqrt{ \frac{10}{3} \times 7 \frac{5}{10} } = \sqrt{ \frac{10}{ 3} \times \frac{75}{10} } = \sqrt{ \frac{75}{3} } = \sqrt{25} = 5$

3.

а)

$7 \sqrt{4 \times 5} + \sqrt{25 \times 5} - 19 \sqrt{5} = 7 \times 2 \sqrt{5} + 5 \sqrt{5} - 19 \sqrt{5} = 14 \sqrt{5} + 5 \sqrt{5} - 19 \sqrt{5 } = 0$

б)

$x \sqrt{xy } - x \sqrt{y \times y} + y \sqrt{x \times x} - y \sqrt{xy} = x \sqrt{xy} - xy + xy - y \sqrt{xy} = \\ = x \sqrt{xy} - y \sqrt{xy}$

4.а)

$\frac{(4 - \sqrt{x})(4 + \sqrt{x} ) }{ \sqrt{x + 4} } = 4 - \sqrt{x}$

б)

больше не знаю