Find the determinant of the matrix.
| 6 9 1 |
| 9 9 2 |
| 2 8 10 ∣

d = -277
d = -278
d = -279
d = -276
d = -272

-276

Step-by-step explanation:

We'll use the method of cofactors.  Use the coefficient +6 for

9   2

8   10

This gives you one third of the solution:  6 {(9)·(10) - (8)(2) },  or 444.

Next, use the coefficient 9, taking care to change the sign to -9  as follows:

     9   1

-9 |           |     =   -9(90 - 8) = -9(82) = -738  

      8  10

Finally with +2 as y our coefficient, evaluate the cofactor

9  1

9  2

ending up with  

+2(18-9) = +2(9) = 18

Finally add these three results together:

+444 - 738 + 18  =  -276

This, the determinant, D, is -276 (the fourth answer choice)