Determinant of a $3 \times 3$ matrix

Question

I have a matrix of order $3 \times 3$. When I take its determinant it give 1700 from all the rows and columns except row 2. I don`t know whats going on

$$\begin{bmatrix}1&20&0\\0&0&10\\10&30&20\end{bmatrix}$$

Answer 1

$$\pmatrix{1&20&0\\0&0&10\\10&30&20}$$

If you use the second row, you get $(-10) \cdot (30-200)=(-10)\cdot (-170)=1700$

Note that the sign-scheme is

$+\ -\ +$

$-\ +\ -$

$+\ -\ +$

Answer 2

$$\left| \begin{array}{ccc} 1&20&0\\ 0&0&10\\ 10&30&20\\\end{array} \right|$$ $$=-0\cdot\left|\begin{array}{cc}20 & 0\\30&20\end{array}\right| +0\cdot\left|\begin{array}{cc}1 & 0\\10&20\end{array}\right| -10\cdot\left|\begin{array}{cc} 1 & 20\\10&30\end{array}\right|$$ $$=-0 + 0 -10(1\cdot30-20\cdot10)$$ $$=-10\cdot(30-200) = -10\cdot(-170)$$ $$=+1700$$