Question

СОР помогите СТАВКИ ВЫСОКИ♣50♣БАЛЛОВ

Answer 1

1.

а) $\sqrt{64} =\sqrt{8^{2}} =8$

б) $\sqrt{1.69} =\sqrt{(1.3)^{2}} =1.3$

2.

$\sqrt{5x} -\sqrt{20x} +\sqrt{45x} =\sqrt{5x} -\sqrt{4*5x} +\sqrt{9*5x} =\sqrt{5x} -2\sqrt{5x} +3\sqrt{5x} =2\sqrt{5x}$

3.

$3\sqrt{6}=\sqrt{9*6} =\sqrt{54}$

$2\sqrt{7} =\sqrt{4*7} =\sqrt{28}$

$\sqrt{54}>\sqrt{28}$

$3\sqrt{6}>2\sqrt{7}$

4.

$(5\sqrt{7} -3\sqrt{2})\sqrt{7} +3\sqrt{14} =5*7-3\sqrt{14} +3\sqrt{14} =35$

5.

$\frac{1}{2\sqrt{6} -5} -\frac{1}{2\sqrt{6} +5} =\frac{2\sqrt{6} +5}{(2\sqrt{6} -5)(2\sqrt{6} +5)} -\frac{2\sqrt{6} -5}{(2\sqrt{6} -5)(2\sqrt{6} +5)} =\frac{10}{(2\sqrt{6})^{2}-25 } =-10$