Răspuns:
Explicație pas cu pas:
[tex]\left|\begin{array}{ccc}x&-2&3\\-2&3&x\\3&x&-2\end{array}\right| =0[/tex]
x -2 3
-2 3 x
-6x-6x-6x-(27+x³-8)=0
-18x-19-x³=0 |×(-1)
x³+18x+19=0
x³+1+18x+18=0
(x+1)(x²-x+1)+18(x+1)=0
(x+1)(x²-x+19)=0
x=-1
x²-x+19=0
Δ=1-76=-75<0 nu are solutii reale
ramane x=-1
