Question

ПОМОГИТЕ РЕШИТЬ ПРИМЕРЫ КРОМЕ 1

ПОЙЖАЛУСТА ПОМОГИТЕ!!!!!!!!!!!!!!!!!!!!​

Answer 1

Пошаговое объяснение:

б)

$x {}^{2} + 2x + x + 2 = 4 {x}^{2} - 20x - \\ 20x + 10 \\ {x}^{2} + 3x + 2 = 4 {x}^{2} - 22x + 10 \\ {x}^{2} + 3x + 2 - 4 {x}^{2} + 22x - 10 = x \\ - 3 {x}^{2} + 25x - 8 = 0 \\ - 3 {x}^{2} - 25x + 8 = 0 \\ d = - 25 {}^{2} - 4 \times 3 \times 8 = 625 - 96 = 529 \\ x(1.2) = \frac{ - ( - 25) + - \sqrt{529} }{2 \times 3} = \frac{25 + - 23}{6 } \\ x(1) = \frac{25 + 23}{6} = \frac{48}{6} = 8 \\ x(2) = \frac{25 - 23}{6} = \frac{2}{6} = \frac{1}{3}$

в)

$\frac{ {x}^{2} }{5 } - \frac{2x}{3} = \frac{x + 5}{6} ( \times 30) \\ 6 {x}^{2} - 20x = 5(x + 5) \\ 6 {x}^{2} - 20x = 5x + 25 \\ 6x {}^{2} - 20x - 5x - 25 = 0 \\ 6x {}^{2} - 25 x - 25 = 0 \\ d = - 25 {}^{2} - 4 \times 6 \times ( - 25) = - 25( - 25 - 4 \times 6) = - 25( - 49) = 1225 \\ x(1.2) = \frac{( - 25) + - \sqrt{1225} }{6 \times 2} = \frac{25 + - 35}{12} \\ x(1) = \frac{25 + 35}{12} = \frac{60}{12} = 5 \\ x(2) = \frac{25 - 35}{12} = \frac{ - 10}{12} = - \frac{5}{6}$

г)

$\frac{x {}^{2} }{6} - \frac{2x}{3} = \frac{3x - 10}{4} ( \times 12) \\ 2x {}^{2} - 8x = 3(3x - 10) \\ 2 {x}^{2} - 8x = 9x - 30 \\ 2 {x}^{2} - 8x - 9x + 30 = 0 \\ 2 {x}^{2} - 17x + 30 = 0 \\ d = - {17}^{2} - 4 \times 2 \times 30 = 289 - 240 = 49 \\ x(1.2) = \frac{ - ( - 17) + - \sqrt{49} }{2 \times 2} = \frac{17 + - 7}{4} \\ x(1) = \frac{17 + 7}{4} = \frac{24}{4} = 6 \\ x(2) = \frac{17 - 7}{4} = \frac{10}{4} = \frac{5}{2} = 2 \frac{1}{2}$