Quote:

$\displaystyle A\:=\:\begin{vmatrix}7&\text{-}4&\text{-}6 \\2&0&\text{-}3 \\ 1&2&\text{-}5\end{vmatrix}$

$\displaystyle \text{Evaluate }|A|\text{ by expanding down the third column.}$

$\displaystyle \text{I get: }\:[\text{-}6(\text{-}1)^4(3)]+[\text{-}3(\text{-}1)^5(18)]+[\text{-}5(\text{-}1)^6(8)]$ . Not sure what all this is.

. . . $\displaystyle =\;\text{-}6(3)+3(18)-5(8) \;=\;-4$

Answer is supposed to be -10, which i've arrived at expanding another row and column.

What am I doing wrong?