Question
Question: If $\begin{bmatrix} 6 & -31 & 1 \\ 4 & 31 & -1 \\ 20 & 3 & 1 \end{bmatrix}$ = x+y, then (x,y) is...
If 6420−313131−11 = x+y, then (x,y) is

A
(2,3)
B
(1,2)
C
(3,1)
D
(0,0)
Answer
(1,2)
Explanation
Solution
The problem states a matrix equals x+y. This implies x+y is a scalar value derived from the matrix. By calculating various scalar properties of the matrix (determinant, trace, sum of all elements, sum of rows/columns), we find that the sum of the elements in the second column is 3. Among the given options, only (1,2) yields a sum of 3 (1+2=3). Therefore, it is inferred that the question implicitly asks for x+y to be the sum of the elements of the second column.