tolong d jawab sebelumnya terima kasih..

jawab
(9)

[tex] \left[\begin{array}{ccc}x&-3\\-2&x-1\end{array}\right] \,=6 [/tex]

x(x-1) - (-2)(-3)= 6
x² - x - 6 - 6 = 0
x² - x - 12 =0
(x - 4)(x + 3) = 0
x = 4  atau x = - 3

(10)

[tex] det\,D\,= \left[\begin{array}{ccc}2&-3\\4&1\end{array}\right]\,=2(1)-4(-3)=14[/tex]

[tex] det\, X\,= \left[\begin{array}{ccc}-18&-3\\-8&1\end{array}\right]\,=-18(1) - (-8)(-3) = -42 [/tex]

[tex] det\, Y\,= \left[\begin{array}{ccc}2&-18\\4&-8\end{array}\right]\,=2(-8)-4(-18)=56[/tex]

x= DX/D = -42/14 = - 3

y = DY/D = 56/14 = 4