Question

anyone please answer this question

Answer 1

Answer:

3,8 are cofactors of-1,9

Answer 2

Answer:

Co-factor of -1 = 8

Co-factor of 9 = -3

Step-by-step explanation:

w.k.t., co-factor of an element $a_{ij}$ of a matrix is equal to $M_{ij}*(-1)^{i+j}$, where $M_{ij}$ is minor of element $a_{ij}$.

Minor of an element $a_{ij}$ is equal to value of determinant of matrix obtained by deleting the $i^{th}$ row and $j^{th}$ column.

Co-factor of -1 = (Minor of -1)×$(-1)^{1+1}$ = 8×1 = 8

Co-factor of 9 = (Minor of 9)×$(-1)^{2+1}$ = 3×-1 = -3

Please mark it as Brainliest.