Question

What is the determinant of

15

18

154

Answer 1

The answer is 15

Explanation:

Answer 2

The determinant is 15.

Explanation:

You need to calculate the determinant of the given matrix.

1. Subtract column 3 multiplied by 3 from column 1 (C1=C1−(3)C3):

`\left[\begin{array}{ccc}-25&-23&9\\0&3&1\\-5&5&3\end{array}\right]`

2. Subtract column 3 multiplied by 3 from column 2 (C2=C2−(3)C3):

`\left[\begin{array}{ccc}-25&-23&9\\0&0&1\\-5&-4&3\end{array}\right]`

3. Expand along the row 2: (See attached picture).

We get that the answer is 15. The determinant is 15.