Предмет: Алгебра, автор: denizabilalova658

Один из корней уравнений x^2+11x+q=0 равен -7. (x^2- это х в квадрате.)

sheinandrei78: х² + 11х + q = 0,

(-7)² + 11*(-7) + q = 0,,

49 - 77 + q = 0,

q = 77 - 49,

q = 28,

х² + 11х + 28 = 0,

Д = 11² - 4*1*28 = 121 - 112 = 9,

х2 = (-11 + 3) / 2*1 = -8/2 = -4

sheinandrei78: вроде так

lerka2339: неверно

sheinandrei78: ну лан)

Ответы

Автор ответа: sheinandrei78

х² + 11х + q = 0,

(-7)² + 11*(-7) + q = 0,,

49 - 77 + q = 0,

q = 77 - 49,

q = 28,

х² + 11х + 28 = 0,

Д = 11² - 4*1*28 = 121 - 112 = 9,

х2 = (-11 + 3) / 2*1 = -8/2 = -4

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