Not sure how to input matrices into latex but its an easy problem:

A=

|7 -4 -6 |

|2 0 -3 |

|1 2 -5 |

Evaluate |A| by expanding down the third column:

I get:

[-6(-1)^{4}(3)]+[-3(-1)^{5}(18)]+[-5(-1)^{6}(8)]

=-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?