Алгебра. Решить примеры:
1) [tex]x^{2}[/tex] = -9x - 8
2) [tex]x^{2}[/tex] - 20x = -5x - 13 - [tex]x^{2}[/tex]

1) x² = -9x - 8; x² + 9x + 8 = 0; x₁ = 8; x₂ = 1. Ответ: 8; 1.

2) x² - 20x = -5x - 13 - x²; x² + x² + 5x - 20x + 13 = 0;  2x² - 15x + 13 = 0;

D = b² - 4ac = 225 - 4·2·13 = 225 - 104 = 121; √D = 11;

x₁ = (15 + 11)/4 = 6,5; x₂ = (15 - 11)/4 = 1.

Ответ: 6,5; 1.

x² = -9x - 8x² + 9x + 8 = 0x² +8x + x + 8 =0x(x+8)+x + 8 = 0(x +8)(x+1) = 0x+8=0x+1=0 x=-8x=-1x1=-8x2=-12)x² - 20x = -5x - 13 - x²x² - 20x + 5x + 13 + x² = 02x² - 15x + 13 = 02x² - 2x - 13x + 13 = 02x(x-1) - 13(x -1) = 0(x-1)(2x -13) = 0x-1 = 02x - 13 = 0x= 1x = 13/2 = 6,5x1= 1x2 = 6,5