Решебник по алгебре 8 класс Мерзляк Задание 637

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\[1)\ x² - 6x + 8 = 0\]

\[x^{2} - 4x - 2x + 8 = 0\]

\[x(x - 4) - 2 \cdot (x - 4) = 0\]

\[(x - 4)(x - 2) = 0\]

\[x = 4,\ \ x = 2\]

\[Ответ:x = 4;x = 2.\]

\[2)\ x² + 12x + 20 = 0\]

\[x^{2} + 10x + 2x + 20 = 0\]

\[x(x + 10) + 2 \cdot (x + 10) = 0\]

\[(x + 10)(x + 2) = 0\]

\[x = - 10,\ \ x = - 2\]

\[Ответ:\ x = - 10;\ x = - 2.\]

\[3)x² + 22x - 23 = 0\]

\[x^{2} + 23x - x - 23 = 0\]

\[x(x + 23) - (x + 23) = 0\]

\[(x + 23)(x - 1) = 0\]

\[x = - 23,\ \ x = 1\]

\[Ответ:\ x = - 23;x = 1.\ \]