Question

Solve $\left|\begin{array}{ccc}x& -4& -4\\ 3& 2& 1\\ -2& 4& 1\end{array}\right|$ =0

Answer 1

$\left|\begin{array}{ccc}x& -4& -4\\ 3& 2& 1\\ -2& 4& 1\end{array}\right|=0$

$x(2-4)+4(3+2)-4(12+4)=0$

$-2x+20-64=0$

$-2x=44$

$x=-22$