Question

could anyone help me step by step on how to do this?
find the value of the variable
[-12 -w^2] = [2k -81]
[2f 3 ] [-14 3]

2. evaluate the determinant of the matrix
{-4 5 6]
[0 4 4]
[-2 -5 4]

Answer 1

[-12 -w^2] = [2k -81]
comparing the terms at the like places we have:

-12= 2k
k=-6

-w^2= -81
w^2= 81
w = 9

Answer 2

[-12 -w^2] = [2k -81]
[2f 3 ] = [-14 3]

comparing the terms at the like places we have:
-12= 2k
k=-6
-w^2= -81
w^2= 81
w = 9

2f = -14
f= -7