Răspuns:
Explicație pas cu pas:
[tex]\left|\begin{array}{ccc}-4&8\\2x&3\\\end{array}\right| = -12 <=> (-4)*3 - 8*2x = -12 <=> -12-16x = -12 <=> 16x=0 <=> x=0[/tex]
[tex]\left|\begin{array}{ccc}2&x&1\\0&x&-1\\1&2&x\end{array}\right| =3 <=> 2*x*x +0*2*1+x*(-1)*1 -1*x*1 - 0*x*x-2*2*(-1) = 3 <=> 2x^2-x-x+4 = 3<=> 2x^2-2x+1=0[/tex]
Δ=(-2)^2 -4*2*1 = 4-8= -4 => x1/x2 ∉R
