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=
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+
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=
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-
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-
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+
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= 0
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= 0
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= 0
Дробь равна 0, когда числитель = 0, а знаменатель НЕ равен 0
х + 1 ≠ 0 ⇒
х ≠ -1
х -1 ≠ 0 ⇒
х ≠ 1
Решаем квадратное уравнение
х² - 5х + 4 = 0
а = 1; b = -5; c = 4
D = b² - 4ac = (-5)² - 4 * 1 *
4 = 25 - 16 = 9
x1 = - b + √D
= - ( -
5) + √9 = 5 + 3 = 4
2a 2 * 1
2
x2 = - b - √D
= - ( - 5) - √9 =
5 - 3 = 1 - лишний корень
2a 2 * 1 2
Ответ: 4