Question

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Answer 1

1.

а) $\sqrt{10}*\sqrt{160} = \sqrt{1600} = 40$

б) $\sqrt{7}*\sqrt{21}*\sqrt{3} = \sqrt{441} = 21$

в) $\frac{5\sqrt{99}}{8\sqrt{44}} = \frac{5\sqrt{9*11}}{8\sqrt{4*11}} = \frac{15\sqrt{11}}{16\sqrt{11}} = \frac{15}{16}$

2.

$2\sqrt{18}+3\sqrt{8}+3\sqrt{32}-\sqrt{50} = 2\sqrt{9*2} + 3\sqrt{4*2} + 3\sqrt{16*2} - \sqrt{25*2} = 6\sqrt{2}+6\sqrt{2}+12\sqrt{2} - 5\sqrt{2} = 19\sqrt{2}$

3.

a)

$\frac{4x+x-5}{2}=11\\\frac{5x-5}{2}-11=0\\5x-5-22=0\\5x=27\\x=5.4$

б)

$x^2=11\\x1 = \sqrt{11}\\x2 = -\sqrt{11}$

4.

$V = \sqrt{12.5}*\sqrt{5}*\sqrt{10} = \sqrt{625} = 25 cm^3$