Answer:
a. -12
Step-by-step explanation:
The question is about finding 3×3 matrix determinant
The general formulae for finding determinant;
when given a matrix {a b c}
{d e f} = a.x [e f] - b. x [d f] + c .x [d e]
{g h i} [h i] [g i] [g h]
where x=determinant
Substitute values
{-1 5 1 } {a b c}
{4 -2 2} ={ d e f} = -1 x{-2 2} - 5 x {4 2} + 1 x {4 -2}
{1 2 2} {g h i} {2 2} {1 2} {1 2}
=-1 {-4-4} - 5{ 8-2} + 1{ 8--2}
=-1{-8} - 5{6} + 1{10}
= 8- 30 +10
= -12
=
