Вопрос:

Для каждого значения а решите уравнение: (a^2-9a-10)x=3a^2+a-2.

Ответ:


\[\left( a^{2} - 9a - 10 \right)x = 3a² + a - 2\]



\[3a^{2} + a - 2 = 0\]


\[a_{1} + a_{2} = - \frac{1}{3};\ \ a_{1} \cdot a_{2} = - \frac{2}{3}\]


\[a_{1} = \frac{2}{3},\ \ a_{2} = - 1.\]


\[3a^{2} + a - 2 =\]


\[= 3 \cdot \left( a - \frac{2}{3} \right)(a + 1) =\]


\[= (3a - 2)(a + 1).\]


\[a^{2} - 9a - 10 = 0\]


\[a_{1} + a_{2} = 9;\ \ a_{1} \cdot a_{2} = - 10\]


\[a_{1} = 10,\ \ a_{2} = - 1.\]


\[a^{2} - 9a - 10 = (a - 10)(a + 1).\]


\[1)\ \ a = - 1:\]


\[{(( - 1)}^{2} - 9 \cdot ( - 1) - 10) \cdot x =\]


\[= 3 \cdot ( - 1)² + ( - 1) - 2\]


\[0 \cdot x = 0\]


\[\Longrightarrow x - любое.\]


\[2)\ \ a = 10:\]


\[нет\ решения.\]


\[3)\ \ a = \frac{2}{3}:\]


\[x = \frac{3 \cdot \frac{2}{3} - 2}{\frac{2}{3} - 10} = \frac{2 - 2}{- 9\frac{1}{3}} =\]


\[= \frac{0}{- 9\frac{1}{3}} = 0.\]


\[4)\ \ a \neq - 1,\ a \neq 10,\ a \neq \frac{2}{3}:\]


\[x = \frac{3a - 2}{a - 10}.\]


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