Question

Evaluate question number 7

Answer 1

The answer is B.............

Answer 2

Answer: b. 231

Explanation:

Determinant of any Matrix A=
`\left[\begin{array}{ccc}a_(11)&a_(12)&a_(13)\\a_(21)&a_(22)&a_(23)\\a_(31)&a_(32)&a_(33)\end{array}\right]` is given by :-

`\begin{vmatrix}a_(11)&a_(12)&a_(13)\\a_(21)&a_(22)&a_(23)\\a_(31)&a_(32)&a_(33)\end{vmatrix}\\\\=a_(11)(a_(22)a_(33)-a_(23)a_(32))-a_(12)(a_(21)a_(33)-a_(23)a_(31))+a_(13)(a_(21)a_(32)-a_(22)a_(31))`

Similarly,

`\begin{vmatrix}1&2&3\\ -4&3& 6\\2&-7& 9\end{vmatrix}`

`=1(3*9-6*-7)-2(-4*9-6*2)+3(-4*-7-3*2)\\\\=69-2(-48)+3(22)=69+96+66=231`

Hence, b is CORRRECT answer.