Answer
$x-2y+4=0$
Work Step by Step
The general form of a matrix of order $ 3 \times 3$ is:
$\begin{bmatrix} a & b & c \\ d & e & f \\ g & h& i \end{bmatrix}=a(ei-fh) -b(di-fg)+c(dh-eg)$
Use the formula for a line going through two points, $(a,b)$ and $(c,d)$
$\begin{vmatrix} x & y & 1 \\ a & c & 1 \\ b & d & 1 \end{vmatrix} =0$
Now, $D=det \begin{bmatrix} x & y & 1 \\ -4 & 0 & 1 \\ 4 & 4 & 1 \end{bmatrix}$
or, $-4x+8y-16=0$
So, we have: $x-2y+4=0$
