Correct Answer :
Solution :
The correct answer is 117.
Step 1: Identify the given matrices and conditions
We are given the 3 × 3 matrix A:
and the matrix B defined by its columns:
The columns satisfy the following linear equations:
Step 2: Find the inverse of matrix A
To determine the column vectors of B, we can compute the inverse matrix of A, denoted as .
Let us solve the system where:
This gives the system of equations:
1)
2)
3)
Solving for , , and in terms of , , and :
Therefore, the inverse matrix is:
Step 3: Determine the column vectors of B
Now we calculate , , and :
Thus, the matrix B is:
Step 4: Compute the determinant and trace of B
1. Determinant of matrix B ():
We expand along the first row:
So, .
2. Diagonal sum (trace) of matrix B ():
Step 5: Calculate the final value
We need to find the value of :
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