Question

помогите!!!!!!!!!11!!12!

Answer 1

поздно уже, наверное

Answer 2

1)

$\sqrt{x - 5} = 9 \\ x - 5 = 81 \\ x = 86$

2)

$\sqrt{7x - 1} = 3 \\ 7x - 1 = 9 \\ 7x = 10 \\ x = \frac{10}{7}$

3)

$\sqrt{3 - 2x ^{2} } = 1 \\ 3 - 2 {x}^{2} = 1 \\ - 2x {}^{2} = - 2 \\x {}^{2} = 1 \\ x = - 1 (1)$

2 корня 1,-1

4)

$\sqrt{6 + 5x {}^{2} } = 2 \\ 6 + 5x {}^{2} = 4 \\ 5x {}^{2} = - 2 \\ x {}^{2} = - \frac{2}{5}$

Нет корней

5)

$\sqrt{23 + 3x - 5x {}^{2} } = 3 \\ 23 + 3x - 5x {}^{2} = 9 \\ - 5x {}^{2} + 3x + 14 = 0 \\ 5x {}^{2} - 3x - 14 = 0 \\ d = 9 - 4 \times 5 \times - 14 = 289 \\ x = \frac{3 { + - }^{} 17}{10} \\ x = 2 \\ x = - 1.4$

примичание

$x = \frac{3 { + - }^{} 17}{10}$

+- это ±