Question

Решить систему уравнений по формулам Крамера.
x-8y-6z=-6
4x-2y+5z=3
3x-7y-2z=-4

Answer 1

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Answer 2

$\delta = \left|\begin{array}{ccc}1&-8&-6\\4&-2&5\\3&-7&-2\end{array}\right|=\\ =4-120+168-36+35-64=-13\\ \delta_1 = \left|\begin{array}{ccc}-6&-8&-6\\3&-2&5\\-4&-7&-2\end{array}\right|=\\ =-24+160+126+48-210-48=52\\ \delta_2 = \left|\begin{array}{ccc}1&-6&-6\\4&3&5\\3&-4&-2\end{array}\right|=\\ =-6-90+96+54+20-48=26\\ \delta_3 = \left|\begin{array}{ccc}1&-8&-6\\4&-2&3\\3&-7&-4\end{array}\right|=\\ =8-72+168-36+21-128=-39$

$x_1= \frac{\delta_1}{\delta} = \frac{52}{-13} =-4\\ x_2= \frac{\delta_2}{\delta}= \frac{26}{-13} =-2\\ x_3= \frac{\delta_3}{\delta}= \frac{-39}{-13} =3$

Ответ: (-4; -2; 3)