корень из (2X^2-7X-9) минус X=1

перерешаю: 2x^2 - 7x - 9 = x^2 + 2x + 1

2x^2 - 7x - 9 - x^2 - 2x - 1 = 0 x^2 - 9x - 10 = 0

D = 81 - 4 * ( - 10) = 81 + 40 = 121 x1 = 9 + 11/2 = 10, x2 = 9 - 11/2 = - 2/2 = -1

значит,ответ: x1 = 10, x2 = - 1

вот теперь сошлось)

√ ( 2x² - 7x - 9) - x = 1√ ( 2x² - x - 9) = x + 12x² - x - 9 = ( x + 1)²2x² - x - 9 = (x + 1)(x + 1)2x² - x - 9 = x² + x + x + 12x² - x - 9 = x² + 2x + 12x² - x - 9 - x² - 2x - 1 = 0x² - 3x - 10 = 0D = b² - 4ac = 9 - 4 × 1 × ( - 10 ) = 9 + 40 = 49 = 7²x₁ = 3 + 7 / 2 = 5x₂ = 3 - 7 / 2 = - 4 / 2 = - 2Ответ: x₁ = 5, x₂ = - 2