ini susah bagi saya tolong kerjakan ya!

artinya determinan [tex] \left[\begin{array}{ccc}x&-4&\x&x&x\end{array}\right] = [/tex] determinan [tex] \left[\begin{array}{ccc}4&1\\7&3\end{array}\right] [/tex]
shg
(x.x) - (-4 .x) = (4.3) - (1 . 7)
x²+4x = 12-7
x²+4x=5
x²+4x-5 = 0
(x - 1)(x + 5) = 0
x-1=0  atau x+5 = 0
x  = 1  atau    x = -5