1) (x - 1)(x - 2) + (x + 3)(x - 3) + 3x + 18 = 0
x² - 2x - x + 2 + x² - 9 + 3x + 18 = 0
2x² + 11 = 0
x² = - 5,5 - решений нет
2) (3x - 5)² - 5(5 - 6x) = 0
9x² - 30x + 25 - 25 + 30x = 0
9x² = 0
x² = 0
x = 0
3) (x - 7)² + 7(2x - 14) = 0
x² - 14x + 49 + 14x - 98 = 0
x² - 49 = 0
x² = 49
<span>2+3(y-1/3)-2(0.5y)</span>
<span>2+3(y-1/3)-2(0.5y)</span>
<span>2+3y-1-y</span>
<span>1+2y</span>
<span>
</span>
x² = 30 - x
x² + x - 30 = 0
a = 1; b = 1; c = - 30
D = b² - 4ac = 1² - 4 * 1 * (-30) = 1 + 120 = 121
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x1 = (-1+11)/2
x1 = 10/2
x1 = 5
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x2 = (-1-11)/2
x2 = -12/2
x2 = -6
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Ответ: x1 = 5, x2 = -6.
Решение во вложенииииииииииииии